Message field needs vertical scrollbar in Create Tag dialog

What steps will reproduce the problem?

1. Open Create Tag... dialog.
2. Type a very long entry in the Message field such that the number of lines exceeds the visible number of lines.

What is the expected output? What do you see instead?

I would expect a vertical scrollbar to either always be present or to appear after the number of visible lines has been exceeded. As is, no scrollbar ever appears which makes navigating long messages more cumbersome.

What version of TortoiseGit and Git are you using? On what operating system?

2.5.0.0

Please provide any additional information below.

See annotated screenshot below.