Merge pull request #23 from msgflo/fix-mqtt-falsy

mqtt: Fix falsy messages not being sent

Author: jonnor

src/mqtt.coffee

@@ -105,7 +105,7 @@ class Client extends interfaces.MessagingClient
     handlers = @subscribers[topic]
 
     debug 'message', handlers.length, msg != null
-    return if not msg or not handlers
+    return if not handlers
     out =
       data: msg
       mqtt: message

src/routing.coffee

@@ -60,6 +60,7 @@ class Binder
     binding = @bindings[id]
     return callback new Error "Binding does not exist" if not binding
     binding.enabled = false
+    delete @bindings[id]
     #FIXME: add an unsubscribeQueue to Client/transport, and use that
     return callback null