mcd-account: use proper gboolean rather than 1 bit to store boolean properties
mcd-account: use proper gboolean rather than 1 bit to store boolean properties

It doesn't make sense to not use the boolean type provided by our framework
and using 1 bit variable introduces weird corner case when being casted with
gboolean.

https://bugs.freedesktop.org/show_bug.cgi?id=40545
Reviewed-by: Will Thompson <5822fdda638242a44ccfa68f146ccf6f257c5cbd@collabora.co.uk>

freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control