Put the mkdir at the beginning of the script

Now it's just written once, but it covers the two previous cases where it was used.

docker/run.sh

@@ -6,16 +6,16 @@ function fixperms {
 
 cd /opt/maubot
 
+mkdir -p /var/log/maubot /data/plugins /data/trash /data/dbs
+
 if [ ! -f /data/config.yaml ]; then
 	cp docker/example-config.yaml /data/config.yaml
-	mkdir -p /var/log /data/plugins /data/trash /data/dbs
 	echo "Config file not found. Example config copied to /data/config.yaml"
 	echo "Please modify the config file to your liking and restart the container."
 	fixperms
 	exit
 fi
 
-mkdir -p /var/log/maubot /data/plugins /data/trash /data/dbs
 alembic -x config=/data/config.yaml upgrade head
 fixperms
 exec su-exec $UID:$GID python3 -m maubot -c /data/config.yaml -b docker/example-config.yaml