fix: give docker user storge directory permissions for fileupload

Dockerfile

@@ -53,9 +53,10 @@ RUN export DATABASE_URL=mysql2://localhost/temp?encoding=utf8 && \
     rm -Rf /var/lib/apt/lists/* /var/cache/apt/*
 
 # Make relevant dirs and files writable for app user
-RUN mkdir -p tmp && \
+RUN mkdir -p tmp storage && \
     chown nobody config/app_config.yml && \
-    chown nobody tmp
+    chown nobody tmp && \
+    chown nobody storage
 
 # Run app as unprivileged user
 USER nobody