webkit-patch should add reviewer if "Reviewed by NOBODY ..." is missing

webkit-patch should add reviewer if "Reviewed by NOBODY ..." is missing
https://bugs.webkit.org/show_bug.cgi?id=67935

Patch by Balazs Ankes <bank@inf.u-szeged.hu> on 2012-06-20
Reviewed by Ryosuke Niwa.

* Scripts/webkitpy/common/checkout/changelog.py:
(ChangeLog.set_reviewer):
* Scripts/webkitpy/common/checkout/changelog_unittest.py:
(test_set_reviewer):
(test_set_short_description_and_bug_url):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@120821 268f45cc-cd09-0410-ab3c-d52691b4dbfc