[1.1.X] Fixed #12101 -- `OGRGeometry` does not need to create a clone of the...

[1.1.X] Fixed #12101 -- `OGRGeometry` does not need to create a clone of the `SpatialReference` object upon assignment.

Backport of r11707 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@11708 bcc190cf-cafb-0310-a4f2-bffc1f526a37