docker-compose fix for mqtt

mqtt/docker-compose.template

@@ -3,17 +3,8 @@
 
   mqtt:
     build: mqtt
-    volumes:
-      - type: bind
-        source: /home/dirk/tmp/mqtt/
-        target: /mosquitto/
     ports:
-      - target: 1883
-        published: 1883
-        protocol: tcp
-        mode: host
-      - target: 9001
-        published: 9001
-        protocol: tcp
-        mode: host
-
+      - "1883:1883"
+      - "9001:9001"
+    volumes:
+      - /opt/mqtt:/mosquitto