Fix search.html template for Tipue 7.0
Fix search.html template for Tipue 7.0

Cherry picked from commit
getpelican/pelican-themes@6a93a9b5eaae1fe352b7b534a6b14a599343b7b9.

StevenMaude/pelican-bootstrap3-sm,StevenMaude/pelican-bootstrap3-sm