Fix ordering in app.ini and fix run mode option (#2829)

docker/etc/s6/gitea/setup

@@ -21,7 +21,7 @@ if [ ! -f /data/gitea/conf/app.ini ]; then
 
     # Substitude the environment variables in the template
     APP_NAME=${APP_NAME:-"Gitea: Git with a cup of tea"} \
-    APP_MODE=${APP_MODE:-"dev"} \
+    RUN_MODE=${RUN_MODE:-"dev"} \
     SSH_DOMAIN=${SSH_DOMAIN:-"localhost"} \
     HTTP_PORT=${HTTP_PORT:-"3000"} \
     ROOT_URL=${ROOT_URL:-""} \

docker/etc/templates/app.ini

@@ -1,6 +1,7 @@
-[repository]
 APP_NAME = $APP_NAME
-APP_MODE = $APP_MODE
+RUN_MODE = $RUN_MODE
+
+[repository]
 ROOT = /data/git/repositories
 
 [repository.upload]