Fix clean_dst function of BaseCopier
Fix clean_dst function of BaseCopier

Clean_dst has an error with remote runner, it sets the bool value
for string variable "gateway".

MirantisWorkloadMobility/CloudFerry,SVilgelm/CloudFerry,mgrygoriev/CloudFerry,SVilgelm/CloudFerry,MirantisWorkloadMobility/CloudFerry,mgrygoriev/CloudFerry,MirantisWorkloadMobility/CloudFerry,mgrygoriev/CloudFerry,mgrygoriev/CloudFerry,MirantisWorkloadMobility/CloudFerry,SVilgelm/CloudFerry,SVilgelm/CloudFerry