Update s6 path following package update

Dockerfile

@@ -19,4 +19,4 @@ RUN ./docker/build.sh
 VOLUME ["/data"]
 EXPOSE 22 3000
 ENTRYPOINT ["docker/start.sh"]
-CMD ["/usr/bin/s6-svscan", "/app/gogs/docker/s6/"]
+CMD ["/bin/s6-svscan", "/app/gogs/docker/s6/"]

docker/start.sh

@@ -52,5 +52,5 @@ fi
 if [ $# -gt 0 ];then
     exec "$@"
 else
-    exec /usr/bin/s6-svscan /app/gogs/docker/s6/
+    exec /bin/s6-svscan /app/gogs/docker/s6/
 fi