Merge branch 'master' into fix_activity_rights

src/Bundle/ChillActivityBundle/Service/DocGenerator/ActivityContext.php

@@ -130,8 +130,10 @@ class ActivityContext implements
                         return $this->personRender->renderString($p, []);
                     },
                     'multiple' => false,
+                    'required' => false,
                     'expanded' => true,
                     'label' => $options[$key . 'Label'],
+                    'placeholder' => $this->translator->trans('Any person selected'),
                 ]);
             }
         }