Fix potential merge conflict with 20200610-templates-quotePorts

I forgot that 20200610-templates-quotePorts had not been applied yet
and I did not notice when I deleted 9001 that 1883 was not quoted.
Hoping this will avoid the conflict.

Author: Paraphraser

.templates/mosquitto/service.yml

@@ -4,7 +4,7 @@
     restart: unless-stopped
     user: "1883"
     ports:
-      - 1883:1883
+      - "1883:1883"
     volumes:
       - ./volumes/mosquitto/data:/mosquitto/data
       - ./volumes/mosquitto/log:/mosquitto/log