A committed edit no longer shows in git status. You look for it in the history — with the author's name and the date.
git log --oneline lists commits from newest to oldest: a short hash (the commit's id) and the message. For details there is git log -p -- <file>: every commit that touched the file, with its author, date and diff. git show <hash> shows a single commit the same way. git opens long output in less: space pages down, q quits.
When you know the line but not the commit, use git blame <file>. It prints the whole file and puts next to every line the hash, the author and the date of the commit that changed it last. Reading the history — in the Wiki.
Since last week uploads to lab-site larger than 2 MB get a 413 response — the request size limit is set by the client_max_body_size line. Find out who set it.
Find who set the upload limit
In /etc/nginx look at the short commit history, then at who changed each line of conf.d/lab-site.conf and when.