NetworkClient: initialize client_active and profilemanager_thread

StopClient guards profilemanager_thread and nulls it after the delete,
but nothing ever set it, so destroying a client that never started
read an uninitialized pointer. client_active was unset until
StartClient and is read on the same path.

NetworkClient.cpp

@@ -96,6 +96,9 @@ NetworkClient::NetworkClient()
     server_reinitialize                 = false;
     change_in_progress                  = false;
 
+    client_active                       = false;
+    profilemanager_thread               = NULL;
+
     ListenThread                        = NULL;
     ConnectionThread                    = NULL;
 }