gnucash-on-windows master: Turn off building master with mingw, it doesn't work any more.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash-on-windows/commit/2577cc5c (commit)
	from  https://github.com/Gnucash/gnucash-on-windows/commit/df4a3ea0 (commit)



commit 2577cc5c0a4717de5f0ad15801e939ce5675a150
Author: John Ralls <jralls at ceridwen.us>
Date:   Thu Oct 19 10:14:54 2017 -0700

    Turn off building master with mingw, it doesn't work any more.



Summary of changes:
 buildserver/build_periodic.bat | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)