fetch: Fix clobbered user on fetch, round two

Again, fix issue where multiple mails fetched in the same fetch run will set
the user of each of the mails to the user of the first email fetched.

The previous patch neglected to pass the new $cache argument through the
inherited UserForm::getFields() function.

include/class.dynamic_forms.php

@@ -144,8 +144,8 @@ class UserForm extends DynamicForm {
         return $os->filter(array('type'=>'U'));
     }
 
-    function getFields() {
-        $fields = parent::getFields();
+    function getFields($cache=true) {
+        $fields = parent::getFields($cache);
         foreach ($fields as $f) {
             if ($f->get('name') == 'email') {
                 $f->getConfiguration();