Implemention of slack import feature.

api/channel.go

@@ -397,7 +397,7 @@ func JoinChannel(c *Context, channelId string, role string) {
 	}
 }
 
-func JoinDefaultChannels(c *Context, user *model.User, channelRole string) *model.AppError {
+func JoinDefaultChannels(user *model.User, channelRole string) *model.AppError {
 	// We don't call JoinChannel here since c.Session is not populated on user creation
 
 	var err *model.AppError = nil