Docker: Allow to run dev and prod container simultaneously

Mapping the dev container to local TCP port 334112 since the default
port is 334111 to avoid problems when running a prod and dev instance
simultaneously.

docker-compose.dev.yml

@@ -12,5 +12,5 @@ services:
       - .:/Mailpile
       - .dev-mailpile-data:/mailpile-data:rw
     ports:
-      - 33411:33411
+      - 33412:33411