Bug 1286877 - do not set c-basic-offset for python-mode; r=gps

This removes the unnecessary setting of c-basic-offset from all
python-mode files.

This was automatically generated using

    perl -pi -e 's/; *c-basic-offset: *[0-9]+//'

... on the affected files.

The bulk of these files are moz.build files but there a few others as
well.

MozReview-Commit-ID: 2pPf3DEiZqx

toolkit/components/gfx/moz.build

@@ -1,4 +1,4 @@
-# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this