[1.7.x] Fixed #22882 -- Fixed a UnicodeDecodeError in flush.

Thanks djbaldey for the report.

Backport of 0e4d79c4f0 from master

django/core/management/commands/flush.py

@@ -1,3 +1,5 @@
+from __future__ import unicode_literals
+
 import sys
 from importlib import import_module
 from optparse import make_option

docs/releases/1.7.1.txt

@@ -10,3 +10,6 @@ Bugfixes
 ========
 
 * Replace with actual issue (:ticket:`00000`).
+
+* Fixed a ``UnicodeDecodeError`` when the ``flush`` error message contained
+  Unicode characters (:ticket:`22882`).