BUG: notmuch dump --include=properties implies --include=tags

[David Bremner]

This is almost certainly my fault, but

% notmuch dump --include=properties '*'

also includes the (typically much more voluminous) tag information.

I looks like the call to dump_tags_message on line 253 needs to be
guarded by (include & DUMP_INCLUDE_TAGS).

I'm not sure how serious a bug this is, e.g. if it's worth fixing for
debian stretch.

d