Diff/commit search should still show how many repositories timed out when a single repo error occurred

Created by: slimsag

Problem

The following query shows an error for an empty repository, but fails to tell me how many repositories have timed out (in fact, almost all of them have -- see https://github.com/sourcegraph/sourcegraph/issues/5519):

https://k8s.sgdev.org/search?q=type:diff+jre8+timeout:2m

Solution

We should always show how many repositories timed out, not just the error. i.e. the fact that a single repository was failed in our search should not affect the other potential results in this case.

Next steps: investigate why we aren't showing the # of timed out repositories here.

Reported by a user at https://app.hubspot.com/contacts/2762526/company/407948923