Twenty Fourteen: Clean-up some inconsistencies in content-xx.php

[iamtakashi]

This is minor and just clean-up. It's just something I noticed while I was checking something else.

[lancewillett]

In 26036:

Twenty Fourteen: clean up inconsistencies in content template files. Props iamtakashi, fixes #25868.

[iamtakashi]

Further clean-up: Since the Featured Content uses a tag, has_tag() check returns true for featured posts and the posts end up having empty footer element that causes extra vertical margins.

[lancewillett]

In 26048:

Twenty Fourteen: fix case of featured posts has_tag() check that was adding an empty footer element. See #25868, props iamtakashi.