Issue #2506445 by joelpittet, Ryan Weal, Sutharsan, alexpott, subhojit777,...

Issue #2506445 by joelpittet, Ryan Weal, Sutharsan, alexpott, subhojit777, justAChris, nlisgo, effulgentsia, rpayanm, larowlan, chx, xjm, dawehner, geertvd, lauriii, izus, andypost, borisson_, Sharique: Replace !placeholder with @placeholder in t() and format_string() for non-URLs in tests