prune: check package.json before running
prune: check package.json before running

Fixes #3755.

xalopp/npm,DaveEmmerson/npm,yibn2008/npm,xalopp/npm,Volune/npm,ekmartin/npm,cchamberlain/npm,kemitchell/npm,haggholm/npm,DaveEmmerson/npm,segrey/npm,yodeyer/npm,kriskowal/npm,haggholm/npm,DIREKTSPEED-LTD/npm,yodeyer/npm,kriskowal/npm,yibn2008/npm,misterbyrne/npm,segmentio/npm,DIREKTSPEED-LTD/npm,cchamberlain/npm-msys2,yyx990803/npm,evanlucas/npm,evanlucas/npm,segment-boneyard/npm,lxe/npm,evocateur/npm,xalopp/npm,midniteio/npm,segmentio/npm,midniteio/npm,cchamberlain/npm,evanlucas/npm,thomblake/npm,TimeToogo/npm,princeofdarkness76/npm,princeofdarkness76/npm,thomblake/npm,misterbyrne/npm,yyx990803/npm,yodeyer/npm,evocateur/npm,DaveEmmerson/npm,kriskowal/npm,segment-boneyard/npm,yyx990803/npm,thomblake/npm,lxe/npm,misterbyrne/npm,haggholm/npm,chadnickbok/npm,lxe/npm,ekmartin/npm,kimshinelove/naver-npm,rsp/npm,rsp/npm,kemitchell/npm,cchamberlain/npm-msys2,Volune/npm,rsp/npm,segment-boneyard/npm,princeofdarkness76/npm,segrey/npm,evocateur/npm,kimshinelove/naver-npm,cchamberlain/npm,midniteio/npm,segmentio/npm,DIREKTSPEED-LTD/npm,segrey/npm,cchamberlain/npm-msys2,ekmartin/npm,TimeToogo/npm,chadnickbok/npm,Volune/npm,kemitchell/npm,kimshinelove/naver-npm,yibn2008/npm,chadnickbok/npm,TimeToogo/npm