Fix crash if there was no "standard" post format

git-svn-id: http://ios.svn.wordpress.org/trunk@4127 7d847f7c-ffe1-4a24-85be-b788d016d96a
Avoid crashing it the refreshed note has been purged

git-svn-id: http://ios.svn.wordpress.org/trunk@4128 7d847f7c-ffe1-4a24-85be-b788d016d96a