fix bugs in python var ("word") underline regex
fix bugs in python var ("word") underline regex

uschmidt83/SublimeLinter-for-ST2,smanolloff/SublimeLinter3,SublimeLinter/SublimeLinter-for-ST2,simonzack/SublimeLinter3,biodamasceno/SublimeLinter-for-ST2,benesch/sublime-linter,lunixbochs/sublimelint,benesch/sublime-linter,biodamasceno/SublimeLinter-for-ST2,Raynos/SublimeLinter3-raynos,paulirish/SublimeLinter3,lunixbochs/sublimelint,tangledhelix/SublimeLinter-for-ST2,zenlambda/SublimeLinter3,jasonrhaas/SublimeLinter3,ikappas/SublimeLinter3,SublimeLinter/SublimeLinter3,uschmidt83/SublimeLinter-for-ST2,SublimeLinter/SublimeLinter3,smanolloff/SublimeLinter3,paulirish/SublimeLinter3,simonzack/SublimeLinter3,ikappas/SublimeLinter3,zenlambda/SublimeLinter3,jasonrhaas/SublimeLinter3,SublimeLinter/SublimeLinter-for-ST2,tangledhelix/SublimeLinter-for-ST2