docker: add banners/ directory to directories to copy over

docker/php/bootstrap.sh

@@ -25,7 +25,6 @@ fi
 
 # Link the entrypoints from the exposed directory.
 ln -nfs \
-    /code/banners/ \
     /code/tools/ \
     /code/walls/ \
     /code/*.php \
@@ -36,6 +35,7 @@ ln -nfs \
 # Static files accessible from the webserver must be copied.
 cp -ur /code/static /var/www/
 cp -ur /code/stylesheets /var/www/
+cp -ur /code/banners /var/www/
 
 # Ensure correct permissions are set, since this might be bind mount.
 chown www-data /var/www