[1.7.x] Fixed #23802 -- Typos in 1.7 release notes.

Backport of d5a109f6e6 from master

docs/releases/1.7.txt

@@ -1188,7 +1188,7 @@ query string. For example, the URL portion of a cache key is now generated from
 ``http://www.example.com/path/to/?key=val`` rather than ``/path/to/?key=val``.
 The cache keys generated by Django 1.7 will be different from the keys
 generated by older versions of Django. After upgrading to Django 1.7, the first
-request to any previously cached URL will be a cache miss .
+request to any previously cached URL will be a cache miss.
 
 Passing ``None`` to ``Manager.db_manager()``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -1410,8 +1410,8 @@ Miscellaneous
   primary keys with value 0.
 
 * Shadowing model fields defined in a parent model has been forbidden as this
-  creates ambiguity in the expected model behavior. In addition, any clashing
-  fields in the model inheritance hierarchy results in a system check error.
+  creates ambiguity in the expected model behavior. In addition, clashing
+  fields in the model inheritance hierarchy result in a system check error.
   For example, if you use multi-inheritance, you need to define custom primary
   key fields on parent models, otherwise the default ``id`` fields will clash.
   See :ref:`model-multiple-inheritance-topic` for details.
@@ -1710,8 +1710,8 @@ The ``check()`` method has replaced the old ``validate()`` method.
 This method is deprecated in favor of a new ``check_field`` method.
 The functionality required by ``check_field()`` is the same as that provided
 by ``validate_field()``, but the output format is different. Third-party database
-backends needing this functionality should modify their backends to provide an
-implementation of ``check_field()``.
+backends needing this functionality should provide an implementation of
+``check_field()``.
 
 Loading ``ssi`` and ``url`` template tags from ``future`` library
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~