Update UserDefinedForm.php

Casting to integer to prevent potential SQL injection.

code/model/UserDefinedForm.php

@@ -152,7 +152,7 @@ class UserDefinedForm extends Page {
 			);
 
 			// make sure a numeric not a empty string is checked against this int column for SQL server
-			$parentID = (!empty($self->ID)) ? $self->ID : 0;
+			$parentID = (!empty($self->ID)) ? (int)$self->ID : 0;
 
 			// get a list of all field names and values used for print and export CSV views of the GridField below.
 			$columnSQL = <<<SQL