fix Dockerfile

Dockerfile

@@ -42,7 +42,7 @@ EXPOSE 80
 ENV TAIKO_SONGS_URL http://taiko.example.com/songs/
 ENV TAIKO_ASSETS_URL http://taiko.example.com/assets/
 ENV TAIKO_MULTIPLAYER_URL wss://taiko.example.com/p2/
-ENV TAIKO_GIT_URL https://git.example.com/user/repo
+ENV TAIKO_GIT_URL https://git.example.com/user/repo/
 ENV TAIKO_VERSION Nanahira
 ENV TAIKO_EMAIL 78877@qq.com
 ENV TAIKO_REDIS_HOST 127.0.0.1