Fix Windows Activate Process

Author: Hilderin

platform/windows/display_server_windows.cpp

@@ -4727,6 +4727,7 @@ LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARA
 		} break;
 		case WM_EXITSIZEMOVE: {
 			KillTimer(windows[window_id].hWnd, windows[window_id].move_timer_id);
+			windows[window_id].move_timer_id = 0;
 		} break;
 		case WM_TIMER: {
 			if (wParam == windows[window_id].move_timer_id) {