When files are changed inside a folder, git pull fails silently

Problem/Motivation

When files are changed inside a folder (it shouldn't happen but... it happens) the "git pull" operation seems to fail silently. The code is catching exceptions, but the pull doesn't seem to work nor trigger an exception.

Investigate this case.

Steps to reproduce

- Set up a site with demo repos via the quick wizard
- Run cron and parsing jobs
- Change files inside one of the folders with the repo code
- Mark that branch for re-parsing
- Trigger cron and re-parsing again and see what happens

Proposed resolution

Debug Utilities::pullBranch and see if we need to change the error handling for this case.

Maybe also add some extra debugging in case git is not allowed on the server as it is in the same method.

Remaining tasks

MR