[1.7.x] Tweaked strip_tags tests to pass on Python 3.3
[1.7.x] Tweaked strip_tags tests to pass on Python 3.3

Backport of 6a0291bdaf from master.

jyotsna1820/django,oscaro/django,jyotsna1820/django,jyotsna1820/django,jyotsna1820/django,oscaro/django,oscaro/django,oscaro/django