Revert "Update to 0.9.97"

This reverts commit e11e1d4fedaa1fd4a3335d3bee22adcc12950416.

    We cannot release this since it crashes because of
    https://github.com/gogits/gogs/issues/3578

Dockerfile

@@ -15,7 +15,7 @@ RUN passwd -d git
 RUN mkdir -p /home/git/gogs
 ## TODO: use redis as well
 RUN cd /home/git/gogs && \
-    curl -L https://github.com/gogits/gogs/releases/download/v0.9.97/linux_amd64.tar.gz | tar zxvf - --strip-components 1
+    curl -L https://github.com/gogits/gogs/releases/download/v0.9.71/linux_amd64.tar.gz | tar zxvf - --strip-components 1
 
 # setup config paths
 ADD app.ini.template /home/git/app.ini.template