Increase ApproveTestSign timeout to 3 minutes

When installing QWT via qvm-create-windows-qube, the installation may
start while there is sill an Windows installer (OOB?) splash screen that
prevents interacting with any window. In unlucky situation (which
happens always on Windows 11...) the whole 30s timeout expires before
it's possible to interact with the window.

Increase the timeout to (attempt to) fix this issue.

Author: marmarek

src/install-helper/install-helper.c

@@ -170,7 +170,7 @@ int WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPS
 {
     (void)AddSymlinkRightToUsers();
     HANDLE thread = CreateThread(NULL, 0, ApproveTestSign, NULL, 0, NULL);
-    if (WaitForSingleObject(thread, 30000) == WAIT_TIMEOUT)
+    if (WaitForSingleObject(thread, 1800000) == WAIT_TIMEOUT)
         TerminateThread(thread, 0);
     return (int)StopXenbusMonitor();
 }