git-rebase-todo syntax is broken by new git-commit syntax

[0x5c]

trafficstars

Description of the problem or steps to reproduce

#2330 wrongfully added git-rebase-todo to the filename rule of git-commit, overriding the existing git-rebase-todo syntax and thus breaking the ability to highlight rebase todo commands (the commit message syntax is a very different format).

Steps to reproduce:

1. open a file named git-rebase-todo, either manually or while doing an interactive rebase in git
2. observe that the filetype is set to git-commit instead of git-rebase-todo -- the problem has already been reproduced by that point
3. as further observation, a valid rebase command like pick dd26cc7c85 commit message here remains unhighlighted; the command and hash should be in a different colour

Specifications

Commit hash: v2.0.11 tag, built from the tarball on the release page OS: Voidlinux Terminal: Konsole

[0x5c]

An example of the git-rebase-todo syntax working properly, taken in the previous version of micro

[0x5c]

Fixed in #2564