Remove useless test in the |reportLeftRecursion| pass
Remove useless test in the |reportLeftRecursion| pass

Empty sequences are not allowed anymore so we don't have to test for
them.

Mingun/pegjs,Sciumo/pegjs,Sciumo/pegjs,mcanthony/pegjs,luisvt/pegjs,pegjs/pegjs,Mingun/pegjs,mcanthony/pegjs,pegjs/pegjs,luisvt/pegjs,GerHobbelt/pegjs,GerHobbelt/pegjs,jlturner/pegjs,jlturner/pegjs