AbstractBuildForm.php: fixed problem with invalid preg_match() pattern

extension/qfq/qfq/AbstractBuildForm.php

@@ -2978,7 +2978,7 @@ abstract class AbstractBuildForm {
         if (strpos($formElement[FE_FILE_MIME_TYPE_ACCEPT], ',') !== false) {
             $ua = $this->store->getVar('HTTP_USER_AGENT', STORE_CLIENT, SANITIZE_ALLOW_ALNUMX);
             // Look for " Version/11.0 Mobile/15A5370a Safari/" or  " Version/9.0.2 Safari/"
-            $rc = preg_match(' Version\/.*Safari\/', $ua, $matches);
+            $rc = preg_match('; Version/.*Safari/;', $ua, $matches);
             // But not like " Version/4.0 Chrome/52.0.2743.98 Safari/"
             if ($rc == 1 && false === strpos($matches[0], ' Chrome/')) {
                 $formElement[FE_FILE_MIME_TYPE_ACCEPT] = '';