I think removing inner scrollbar for code editor/view and using page natural scroll would be much better solution, the same as it is for Github.com

Othervise on my large monitor i have lot of free space under the editor, and editor looks tiny and code viewing is not handy.
On the smaller monitor i have double scroll - one for page, one for editor which is even worse in usability and reviewing code.

It is very easy to do (CodeMirror has config parameter and some minor css changes), i already customized by myself and suggesting implementing in gitlist core.

Thank you.