Searching % gives an error while trying to load page

[illspirit (optional)]

If you search for anything with % in it and hit Enter, you get an error page.

[tgxworld (Alan Tan)]

Submitted a fix here but I’m still having trouble with writing the tests

https://github.com/discourse/discourse/pull/3607

[tgxworld (Alan Tan)]

@sam lets close this?