Include comment ids in changeset discussion replication files

[Woazboat]

The OSM API recently changed the changeset endpoint to also return the comment id for changeset discussion comments in the api response. The changeset replication should probably be updated to also include this.
openstreetmap/openstreetmap-website#4245

<osm ...>
	<changeset ...>
		...
		<discussion>
			<comment id="1234" ...>
				<text>...</text>
			</comment>
			...
		</discussion>
	</changeset>
</osm>

https://github.com/zerebubuth/openstreetmap-changeset-replication/blob/master/replicate_changesets.rb#L97-L118