Fix #11311 - Do not fail in borg handler when a file has been removed during backup

handlers/borg.in

@@ -175,9 +175,17 @@ debug "$nice $execstr"
 
 if [ $test = 0 ]; then
    output=`$nice su -c "$execstr" 2>&1`
-   if [ $? = 0 ]; then
+   ret=$?
+   if [ $ret = 0 ]; then
       debug $output
       info "Successfully finished backing up source."
+   elif [ $ret = 1 ]; then
+      if (echo "$output" | grep -q 'No such file or directory') ; then
+         debug $output
+      else
+         warning $output
+      fi
+      info "Successfully finished backing up source"
    else
       error $output
       fatal "Failed backing up source."