tracker: Fix AttributeError on ErrorReportif item is None

Closes ArchiveTeam/terroroftinytown#13
tracker: Add Delete All error reports button
style.css: Add missing quotes to fix fonts not used in FIrefox.

Closes ArchiveTeam/terroroftinytown#2
Merge commit '38ceb0c4ade0a729759c5cd1f4ab7f6a1531bc9d'