Set 3000 port for web app in gitlab.yml

According to this line https://gitlab.com/gitlab-org/gitlab-development-kit/blob/master/Makefile#L43 we want GitLab be on port 3000. But gitlab.yml use old 80 port from sample config. This MR fixes it

Makefile

@@ -17,7 +17,7 @@ gitlab-config: gitlab/config/gitlab.yml gitlab/config/database.yml gitlab/config
 gitlab/config/gitlab.yml:
 	sed -e "s|/home/git|${gitlab_development_root}|"\
 	 -e "s|# user: git|user: $(shell whoami)|"\
-	 -e "0,/80/s//3000/"\
+	 -e "0,/port: 80/s//port: 3000/"\
 	 gitlab/config/gitlab.yml.example > gitlab/config/gitlab.yml
 gitlab/config/database.yml: