Fixup .gitignore after PR #1573

[bershanskiy]

Looks like during a rebase .gitignore got extra lines showing the diff of two branches <<<<<<< HEAD, =======, >>>>>>> master. These probably should be removed.

[schalkneethling]

Thank you!

[peterbe]

Oh noes!
We used to have tooling that prevents that from slipping in. Seems it's gone.

[bershanskiy]

Do you mean something like a search for existence of lines like <<<<<<< {something}, =======, >>>>>>> {something}? That's actually a pretty neat idea!

[peterbe]

We used to have something like that in the workflow. It did something like:

 run: git grep '<<<<<<' || (echo "looks like there are merge conflicts in there" && exit 1)