fix: set correctly request->session

The session cookie was not created because request->session pointed at
a temporary session.

While here:
- do some cleaning in App
- set request->mount too
- add fcgi_cannot_create_request_delay to the config
- fix: in mailregister plugin get model_connector from env (and not from the request)

winixd/core/system.cpp

@@ -1445,7 +1445,8 @@ bool System::FollowAllLinks(const std::wstring & link_to,
 			log << log3 << "System: current directory changed and the new file loaded" <<  logend;
 		}
 
-		mounts.CalcCurMount(cur->request);
+		cur->mount = mounts.CalcCurMount(cur->request);
+		cur->request->mount = cur->mount;
 	}
 	else
 	{