Fixed a typo on useradd command

In the last MR I had a small typo, here is the fix for it.

\approve @fd

Dockerfile

@@ -35,8 +35,7 @@ RUN pip3 install shapely --upgrade
 
 COPY ./files/start.sh /usr/local/bin
 
-RUN  useradd -r -u 1000 -g appuser
-appuser
+RUN  useradd -r -u 1000 -g appuser appuser
 USER appuser
 
 CMD ["/usr/local/bin/start.sh"]