Reword mode loses commit message when escaped

### Is your feature request related to a problem? Please describe.

When I use `r` to edit a commit message of a past commit, I sometimes `esc`acpe it, for example to look at the changes again, because I need that to finish writing the message.

When I again use `r` to enter the reword mode, what I wrote before is lost :(

This is inconsistent with the normal commit: If I stage some files, use `c` to start writing commit message, `esc` to look at the changes, and `c` again, the message is still there.

### Describe the solution you'd like

It would be great if `r` also remembered the written commit message.