Remove 500 repos warning

Created by: Joelkw

We actually don't seem to yet support repo: filters in queries so we shouldn't tell you to do this! I left the conditional logic in just because I wasn't sure why we had it/if there's a good reason to show different messages here.

(Also, the original was missing a trailing space, in screenshot – do I need to have that explicitly or did the space I added between . </> take care of it?)