borg: avoid missing directory error duo to double delete

We force delete in the signal handler as a graceful script execution
already deletes the file. This way we avoid any errors being wrongly
printed.

misc/borg.sh

@@ -6,7 +6,7 @@ shopt -s extglob
 OFFSITE_HOST=ch-s012.rsync.net
 
 decrypted_gpg=$(mktemp arch-infrastructure-borg-XXXXXXXXX)
-trap "rm \"${decrypted_gpg}\"" EXIT
+trap "rm -f \"${decrypted_gpg}\"" EXIT
 [[ "$*" =~ $OFFSITE_HOST ]] && is_offsite=true || is_offsite=false
 
 # Find matching key