send exception to syslog for Google drive download

(cherry picked from commit 6d7c1cb7)

src/etc/inc/config.lib.inc

@@ -374,6 +374,7 @@ function backup_to_google_drive()
             $target_filename = "config-" . time() . ".xml";
             if (count($configfiles) > 1) {
                 // compare last backup with current, only save new
+                try {
                     $bck_data_enc_in = $client->download($configfiles[array_keys($configfiles)[0]]);
                     $bck_data_enc = "";
                     tagfile_deformat($bck_data_enc_in, $bck_data_enc, "config.xml");
@@ -381,6 +382,9 @@ function backup_to_google_drive()
                     if ($bck_data == $confdata) {
                         $target_filename = null;
                     }
+                }  catch (Exception $e) {
+                    log_error("unable to download " . $configfiles[array_keys($configfiles)[0]]->description . " from Google Drive (" . $e . ")");
+                }
             }
             if (!is_null($target_filename)) {
                 log_error("backup configuration as " . $target_filename);