Don't append $op if it has not been removed from $k

If getOperator() found an $op, but it is not at the very end of $k, it does not get removed from $k.

Previous code was nevertheless appending $op, so it got repeated a second time in the result, which is obviously wrong.

Author: vlakoff

system/Database/BaseBuilder.php

@@ -659,9 +659,11 @@ protected function whereHaving(string $qbKey, $key, $value = null, string $type
                     $op = trim(current($op));
 
                     if (substr($k, -1 * strlen($op)) === $op) {
-                        $k = rtrim(substr($k, 0, -1 * strlen($op)));
+                        $k  = rtrim(substr($k, 0, -1 * strlen($op)));
+                        $op = " {$op}";
+                    } else {
+                        $op = '';
                     }
-                    $op = " {$op}";
                 } else {
                     $op = ' =';
                 }