Fix broken regexp: filters

We were missing an else, so the real else case was running when it
should not have.

Fixes #10

fields/field.textbox.php

@@ -851,7 +851,7 @@ public function buildDSRetrievalSQL($data, &$joins, &$where, $andOperation = fal
 				$this->buildRegexSQL($data[0], array('value', 'handle'), $joins, $where);
 			}
 
-			if (self::isFilterSQL($data[0])) {
+			else if (self::isFilterSQL($data[0])) {
 				$this->buildFilterSQL($data[0], array('value', 'handle'), $joins, $where);
 			}