Pending connection with colon in username string

[alikh31]

While using this plugin I have notice in case of mqtt client's username containing colon (ex. username = '123:123', password = '123123') the connection would not get rejected nor accepted, it stays suspended. while rabbitMq itself can handle colon in Username string up to some sense.

[michaelklishin]

From MQTT plugin docs:

Authentication
The default_user and default_pass options are used to authenticate the adapter in case MQTT clients provide no login credentials.
If the allow_anonymous option is set to false then clients MUST provide credentials.
The presence of client-supplied credentials over the network overrides the allow_anonymous option.
Colons may not appear in usernames.

The vhost option controls which RabbitMQ vhost the adapter connects to.
The vhost configuration is only consulted if no vhost is provided during connection establishment. 
You can optionally specify a vhost while connecting, by prepending the vhost to the username and separating with a colon.