Fix case when widget was defined with `zle -N widget`
Fix case when widget was defined with `zle -N widget`

Fixes #774

areteix/powerline,magus424/powerline,Liangjianghao/powerline,cyrixhero/powerline,blindFS/powerline,Liangjianghao/powerline,prvnkumar/powerline,bezhermoso/powerline,keelerm84/powerline,bartvm/powerline,s0undt3ch/powerline,keelerm84/powerline,xfumihiro/powerline,xxxhycl2010/powerline,s0undt3ch/powerline,S0lll0s/powerline,bartvm/powerline,bartvm/powerline,dragon788/powerline,QuLogic/powerline,firebitsbr/powerline,kenrachynski/powerline,EricSB/powerline,Luffin/powerline,prvnkumar/powerline,bezhermoso/powerline,Luffin/powerline,seanfisk/powerline,wfscheper/powerline,Luffin/powerline,cyrixhero/powerline,darac/powerline,xfumihiro/powerline,prvnkumar/powerline,xxxhycl2010/powerline,magus424/powerline,lukw00/powerline,seanfisk/powerline,firebitsbr/powerline,QuLogic/powerline,russellb/powerline,seanfisk/powerline,s0undt3ch/powerline,xfumihiro/powerline,IvanAli/powerline,IvanAli/powerline,DoctorJellyface/powerline,blindFS/powerline,bezhermoso/powerline,areteix/powerline,kenrachynski/powerline,EricSB/powerline,kenrachynski/powerline,lukw00/powerline,dragon788/powerline,junix/powerline,blindFS/powerline,QuLogic/powerline,cyrixhero/powerline,firebitsbr/powerline,S0lll0s/powerline,areteix/powerline,xxxhycl2010/powerline,russellb/powerline,DoctorJellyface/powerline,wfscheper/powerline,russellb/powerline,junix/powerline,IvanAli/powerline,DoctorJellyface/powerline,Liangjianghao/powerline,dragon788/powerline,darac/powerline,magus424/powerline,EricSB/powerline,darac/powerline,lukw00/powerline,wfscheper/powerline,S0lll0s/powerline,junix/powerline