Update xenial

Author: ethomson

azure-pipelines/docker/xenial

@@ -64,4 +64,7 @@ COPY entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod a+x /usr/local/bin/entrypoint.sh
 RUN mkdir /var/run/sshd
 
-ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
+RUN useradd --shell /bin/bash libgit2
+RUN chown --recursive libgit2:libgit2 /home/libgit2
+
+USER libgit2