util-cxx: include config.h
util-cxx: include config.h

This avoids a deprecation warning for g_type_init().

Signed-off-by: Simon McVittie <2b470b34502dbf3ba4bcc04ea7e64f4e0e104f33@collabora.co.uk>
Reviewed-by: Xavier Claessens <6f61b6f8ca6f7cbeae6bb087ddf85cf85dce43eb@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=65517

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib