[borg] build/debug prunestr only if prune = yes

handlers/borg.in

@@ -151,10 +151,10 @@ fi
 ### REMOVE OLD BACKUPS ###
 
 # borg prune
+if [ "$prune" == "yes" ]; then
   prunestr="borg prune --keep-hourly $keephourly --keep-daily $keepdaily --keep-weekly $keepweekly --keep-monthly $keepmonthly $execstr_repository"
   debug "$prunestr"
-
-if [ $test = 0 ] && [ "$prune" == "yes" ]; then
+   if [ $test = 0 ]; then
       output="`su -c "$prunestr" 2>&1`"
       if [ $? = 0 ]; then
          debug $output
@@ -164,6 +164,7 @@ if [ $test = 0 ] && [ "$prune" == "yes" ]; then
          warning "Failed removing old backups."
       fi
    fi
+fi
 
 unset BORG_PASSPHRASE