Introduce back override for bad-format-string

It still happens on both Travis and Landscape, though I can not
reproduce it locally.
Signed-off-by: Michal Čihař <michal@cihar.com>

pylint.rc

@@ -25,7 +25,8 @@ load-plugins=pylint_django
 # R0921,R0922 Is raised when abstract classes are used in different module
 # E1002 Produces lot of false positives with Django 1.5
 # R0401(cyclic-import) we have too many of them
-disable=C0111,I0011,I0012,W0142,W0613,W0703,R0201,E1103,E1101,R0401,R0921,R0922,E1002
+# W1302(bad-format-string) looks like a false positive with PyLint 1.3.0
+disable=C0111,I0011,I0012,W0142,W0613,W0703,R0201,E1103,E1101,R0401,R0921,R0922,E1002,W1302
 
 [REPORTS]