talkatu/talkatu

TalkatuAttachment::id is a guint64 not a gint64 so TalkatuMessage needs to use the proper type.

Testing Done:
Just a compile.

Reviewed at https://reviews.imfreedom.org/r/100/
configure_file(
input : 'talkatu.spec.in',
output : 'talkatu.spec',
configuration : version_conf)