fixed issue with contact in group field

Civi/DataProcessor/FieldOutputHandler/GroupsOfContactFieldOutputHandler.php

@@ -68,11 +68,11 @@ class GroupsOfContactFieldOutputHandler extends AbstractFieldOutputHandler {
   public function initialize($alias, $title, $configuration) {
     $this->outputFieldSpecification = new FieldSpecification($alias, 'String', $title, null, $alias);
     $this->contactIdSource = $this->dataProcessor->getDataSourceByName($configuration['datasource']);
-    if (!$this->dataSource) {
+    if (!$this->contactIdSource) {
       throw new DataSourceNotFoundException(E::ts("Field %1 requires data source '%2' which could not be found. Did you rename or deleted the data source?", array(1=>$title, 2=>$configuration['datasource'])));
     }
     $this->contactIdField = $this->contactIdSource->getAvailableFields()->getFieldSpecificationByName($configuration['field']);
-    if (!$this->inputFieldSpec) {
+    if (!$this->contactIdField) {
       throw new FieldNotFoundException(E::ts("Field %1 requires a field with the name '%2' in the data source '%3'. Did you change the data source type?", array(
         1 => $title,
         2 => $configuration['field'],