desktop/version: Use release version from DisplayVersion if available

Reportedly Windows 10 20H2 and later record the feature release id into
DisplayVersion and leave ReleaseId stuck at 2009 for some mysterious
reason. Windows 11 currently will identify itself as Windows 11 21H2
based on this information.

src/desktop/version.cpp

@@ -97,7 +97,11 @@ std::string windows_release_id()
 	char buf[256]{""};
 	DWORD size = sizeof(buf);
 
-	const auto res = RegGetValueA(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "ReleaseId", RRF_RT_REG_SZ, nullptr, buf, &size);
+	auto res = RegGetValueA(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "DisplayVersion", RRF_RT_REG_SZ, nullptr, buf, &size);
+	if(res != ERROR_SUCCESS) {
+		res = RegGetValueA(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "ReleaseId", RRF_RT_REG_SZ, nullptr, buf, &size);
+	}
+
 	return std::string{res == ERROR_SUCCESS ? buf : ""};
 }