.gitmodules: fix xcb-util-m4 url and CI failure
anongit.freedesktop.org doesn't seem to work anymore - using the canonical gitlab https URL instead, so making the CIs work again.
Signed-off-by: Enrico Weigelt, metux IT consult info@metux.net
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anongit.freedesktop.org doesn't seem to work anymore - using the canonical gitlab https URL instead, so making the CIs work again.
Signed-off-by: Enrico Weigelt, metux IT consult info@metux.net