Try and rsync instead of symlinking in the updater

.docker/app/updater.sh

@@ -25,7 +25,7 @@ sed -i.bak "s/^\(memory_limit\) = \(.*\)/\1 = ${PHP_WORKER_MEMORY_LIMIT}/" \
 
 DST_DIR=/var/www/html/tt-rss
 mkdir -p /var/www/html
-ln -s /src/tt-rss /var/www/html/tt-rss
+rsync -a /src/tt-rss/ $DST_DIR/
 
 while [ ! -s $DST_DIR/config.php -a -e $DST_DIR/.app_is_ready ]; do
 	echo waiting for app container...