If the problem is that your shutter speed files do not match the branch, just use git resetusually:
git reset
That should be all you need. However, if you still want to overwrite master with dev, read on.
dev, git reset :
$ git checkout master
$ git reset --hard dev
, - :
$ git push origin master
, dev (, , , , - - ), --force :
$ git push origin master --force
, , a la git rebase - - , .
, , --force . git push, git pull , git push.