Fix Data_Source getColDefault value

SE/se-lib/Data_Source.php

@@ -75,7 +75,7 @@ class Data_Source {
 	}
 
 	public function getColDefault($fieldName) {
-		$fldType = V::get($fieldName, '', $this->_types);
+		$fldType = V::get($fieldName, '', $this->_col_types);
 		if (!$fldType) return '';
 		return V::get('default', '', $fldType);
 	}