Changeset comment reverts to previous when switching options

[Ldp]

• A changeset is already open
• You want to upload something in a new changeset, while keeping the other one open as well
• Start upload, fill in new changeset comment, as that tab is the first to appear.
• Go to Changesets tab, check Upload to a new changeset
• The changeset comment has now reverted to the previous comment, but you only see that if you actually go back to the Settings tab.

It's very easy to miss, and then you upload to the new changeset with the wrong comment.

[Ldp]

Would appreciate if this could be fixed before the next release.

[Gubaer]

(In [3133]) fixed #4371: Changeset comment reverts to previous when switching options