Both file search and plugin repository search reloaded the page when
hitting enter in the search field. This fixes that.
(cherry picked from commit 60043cc)
Doesn't work reliably across pip versions, and adding a special rule for each and every version also isn't fun. Plugin authors will need to use a different approach for pulling in dependencies that are not on pypi during install, e.g. extra install urls or something like that. For now, I give up here ;)
