Fix overlapping elements in Phame for >1791px width
Summary:
Regression from rP9448e815721c882196b8c541560270734574af8e.
Closes T15985
Test Plan:
For both a viewport width >1791px and below,
* Go to the Phriction wiki page http://phorge.localhost/w/blah which has sections so a table of contents is displayed
* Go to http://phorge.localhost/phame/ and with no blogs visible to the current user or no existing blogposts
* Go to http://phorge.localhost/phame/ with existing/visible blogposts, see no overlap of horizontal lines and Blogs box
* Go to an empty blog at http://phorge.localhost/phame/blog/view/4/
* Go to an existing blogpost at http://phorge.localhost/phame/post/view/1/whatever/
* Go to an existing blogpost at http://phorge.localhost/phame/post/view/1/whatever/ which includes a full width image via `{F1234,size=full}`
* Go to http://phorge.localhost/book/phorge/article/remarkup/
* Go to http://phorge.localhost/w/
Reviewers: O1 Blessed Committers, mturdus, avivey
Reviewed By: O1 Blessed Committers, mturdus, avivey
Subscribers: mturdus, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T15985
Differential Revision: https://we.phorge.it/D25873
12991c0d37