Setup references non-existent `master` branch in UtilsLite submodule

[pvazteixeira-humatics]

Encountered the following error at setup (ruby setup.rb):

Checking out branch master in submodules/UtilsLite
HEAD is now at 87ac5d6 try to improve Algo748 error check
error: pathspec 'master' did not match any file(s) known to git

It seems UtilsLite does not have a master branch. Changing the following line in sub_branches.yaml from master to main seems to have fixed the issue

Clothoids/sub_branches.yaml

Line 5 in 9149ffe

submodules/UtilsLite: master

With this change I was able to complete setup and compile with rake