B16616: Changed check method 2. refs#16616

extension/Classes/Core/Form/TypeAhead.php

@@ -71,7 +71,7 @@ class TypeAhead {
 
         // Check for an optional given dbIndex: '[<int>]SELECT ...'
         $sql = $sipVars[FE_TYPEAHEAD_SQL] ?? '';
-        if ($sql[0] ?? '' === '[') {
+        if (($sql[0] ?? '') === '[') {
             $pos = strpos($sql, ']');
             $dbIndex = substr($sql, 1, $pos - 1);
             $sipVars[FE_TYPEAHEAD_SQL] = substr($sql, $pos + 1);