Fix to function imports - only flag known nodes, empty function results allowed
Fix to function imports - only flag known nodes, empty function results allowed

foresthz/less.js,SkReD/less.js,less/less.js,less/less.js,SkReD/less.js,seven-phases-max/less.js,seven-phases-max/less.js,gencer/less.js,less/less.js,arusanov/less.js,foresthz/less.js,arusanov/less.js,gencer/less.js