tests: Fix compile warning on mingw64
In file included from ../../libs/gst/net/gstntppacket.c:35:0, from netclock-replay.c:25: ../../config.h:546:0: error: "__MSVCRT_VERSION__" redefined [-Werror] #define __MSVCRT_VERSION__ 0x0601 In file included from /usr/x86_64-w64-mingw32/sys-root/mingw/include/crtdefs.h:10:0, from /usr/x86_64-w64-mingw32/sys-root/mingw/include/stdio.h:9, from netclock-replay.c:21: /usr/x86_64-w64-mingw32/sys-root/mingw/include/_mingw.h:220:0: note: this is the location of the previous definition # define __MSVCRT_VERSION__ 0x0700 https://bugzilla.gnome.org/show_bug.cgi?id=774108