Pressing Enter in the FilterBar when only one filter remains does not run the filtered list

Found while working on #730. Let's say you use an awful lot of filters on the corpus list. Actually, you use all the filters except one.

Or you are a developer, and you just started implementing the filter bar on the process list, and you do not have all the filters yet so you easily get just one filter remaining:

You would normally just press Enter while focusing on the filter bar to run the query, but this time you can't, because #928 (closed) takes precedence and makes the filter bar select the one and only remaining filter. You can do nothing but use the last filter if you want to run the query, and then delete the filter from the URL yourself.