I have hosted the script on my home server:

http://greasemonkey.centaur.ath.cx/cgit_Add_commit_hash_column.user.js

You can install this in Firefoxoids using the Greasemonkey or
Tampermonkey extension, and in Chromides using Tampermonkey.

If you need this on other aliases of Savannah cgit, or on other cgit
instances, just add the corresponding @include patterns. (If you feel
adventurous, replace the host with a *; this will enable the script on
all pages whose URL contains /cgit/ and /log/ in that order.)