Update build-windows-toolchain.bat

Author: compnerd

utils/build-windows-toolchain.bat

@@ -967,9 +967,7 @@ move %PackageRoot%\online\Release\amd64\*.exe %BuildRoot%\artifacts\online\ || (
 move %PackageRoot%\online\Release\amd64\*.msi %BuildRoot%\artifacts\online\ || (exit /b)
 
 :: Workaround for lack of control over Jenkins ...
-for /F "tokens=*" %%F in ('dir /b %BuildRoot%\artifacts\offline\*') DO (
-  copy %F %BuildRoot%\artifacts\ || (exit /b)
-)
+copy %BuildRoot%\artifacts\offline\installer.exe %BuildRoot%\artifacts\
 
 goto :eof
 endlocal