[1.11.x] Removed extra characters in docs header underlines.

Backport of a3af8c99d9 from master

docs/faq/troubleshooting.txt

@@ -11,7 +11,7 @@ Problems running ``django-admin``
 =================================
 
 "command not found: `django-admin`"
-------------------------------------
+-----------------------------------
 
 :doc:`django-admin </ref/django-admin>` should be on your system path if you
 installed Django via ``python setup.py``. If it's not on your path, you can

docs/ref/checks.txt

@@ -15,7 +15,7 @@ API reference
 =============
 
 ``CheckMessage``
------------------
+----------------
 
 .. class:: CheckMessage(level, msg, hint=None, obj=None, id=None)
 

docs/ref/contrib/gis/tutorial.txt

@@ -53,7 +53,7 @@ would for any other project. We provide some tips for selected databases:
 * :doc:`install/spatialite`
 
 Create a New Project
-------------------------
+--------------------
 
 Use the standard ``django-admin`` script to create a project called
 ``geodjango``:

docs/ref/contrib/sitemaps.txt

@@ -420,7 +420,7 @@ rendering. For more details, see the :doc:`TemplateResponse documentation
 </ref/template-response>`.
 
 Context variables
-------------------
+-----------------
 
 When customizing the templates for the
 :func:`~django.contrib.sitemaps.views.index` and

docs/ref/databases.txt

@@ -628,7 +628,7 @@ specific to SQLite that you should be aware of.
 .. _sqlite-string-matching:
 
 Substring matching and case sensitivity
------------------------------------------
+---------------------------------------
 
 For all SQLite versions, there is some slightly counter-intuitive behavior when
 attempting to match some types of strings.  These are triggered when using the

docs/ref/models/fields.txt

@@ -356,7 +356,7 @@ respect to the month.
 Like :attr:`~Field.unique_for_date` and :attr:`~Field.unique_for_month`.
 
 ``verbose_name``
--------------------
+----------------
 
 .. attribute:: Field.verbose_name
 
@@ -365,7 +365,7 @@ will automatically create it using the field's attribute name, converting
 underscores to spaces. See :ref:`Verbose field names <verbose-field-names>`.
 
 ``validators``
--------------------
+--------------
 
 .. attribute:: Field.validators
 
@@ -417,7 +417,7 @@ guaranteed to fit numbers from ``-9223372036854775808`` to
 :class:`~django.forms.TextInput`.
 
 ``BinaryField``
--------------------
+---------------
 
 .. class:: BinaryField(**options)
 

docs/ref/models/indexes.txt

@@ -28,7 +28,7 @@ options`_.
     Creates an index (B-Tree) in the database.
 
 ``fields``
------------
+----------
 
 .. attribute:: Index.fields
 

docs/ref/models/options.txt

@@ -330,7 +330,7 @@ Django quotes column and table names behind the scenes.
     human_readable_permission_name)``.
 
 ``default_permissions``
-------------------------------
+-----------------------
 
 .. attribute:: Options.default_permissions
 

docs/ref/settings.txt

@@ -1492,7 +1492,7 @@ Monday and so on.
 .. setting:: FIXTURE_DIRS
 
 ``FIXTURE_DIRS``
------------------
+----------------
 
 Default: ``[]`` (Empty list)
 
@@ -1983,7 +1983,7 @@ See :tfilter:`allowed date format strings <date>`. See also
 .. setting:: NUMBER_GROUPING
 
 ``NUMBER_GROUPING``
---------------------
+-------------------
 
 Default: ``0``
 

docs/topics/conditional-view-processing.txt

@@ -147,7 +147,7 @@ using one of these decorators::
     front_page = last_modified(latest_entry)(front_page)
 
 Use ``condition`` when testing both conditions
-------------------------------------------------
+----------------------------------------------
 
 It might look nicer to some people to try and chain the ``etag`` and
 ``last_modified`` decorators if you want to test both preconditions. However,

docs/topics/db/models.txt

@@ -1362,7 +1362,7 @@ Or use a common ancestor to hold the :class:`~django.db.models.AutoField`::
         pass
 
 Field name "hiding" is not permitted
--------------------------------------
+------------------------------------
 
 In normal Python class inheritance, it is permissible for a child class to
 override any attribute from the parent class. In Django, this isn't usually

docs/topics/db/multi-db.txt

@@ -554,7 +554,7 @@ solution is to use ``db_manager()``, like this::
 ``db_manager()`` returns a copy of the manager bound to the database you specify.
 
 Using ``get_queryset()`` with multiple databases
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 If you're overriding ``get_queryset()`` on your manager, be sure to
 either call the method on the parent (using ``super()``) or do the