Add gs.trustedHosts to form-action csp

This will allow loadbalanced collabora servers to serv frames

Signed-off-by: Micke Nordin <kano@sunet.se>

lib/AppInfo/Application.php

@@ -247,6 +247,7 @@ public function updateCSP() {
 				foreach ($trustedList as $server) {
 					$policy->addAllowedFrameDomain($server);
 					$this->addTrustedRemote($policy, $server);
+					$policy->addAllowedFormActionDomain($server);
 				}
 			}
 			$remoteAccess = $container->getServer()->getRequest()->getParam('richdocuments_remote_access');