Fix pusher channel subscribe

When channel_prefix is not defined it should be set to empty string.

app/app.coffee

@@ -51,7 +51,6 @@ App = Ember.Application.extend(Ember.Evented,
       store.pushPayload(commits: [commit])
 
     if event == 'job:log'
-      console.log 'store: received job:log event', data if Log.DEBUG
       data = data.job
       job = store.recordForId('job', data.id)
       job.appendLog(number: parseInt(data.number), content: data._log, final: data.final)

app/routes/main.coffee

@@ -19,7 +19,7 @@ Route = TravisRoute.extend
 
   activate: ->
     # subscribe to pusher only if we're at a main route
-    if config.pusher.channels
-      @get('pusher').subscribeAll(config.pusher.channels)
+    unless config.pro
+      @get('pusher').subscribeAll(['common'])
 
 `export default Route`

app/utils/pusher.coffee

@@ -38,8 +38,9 @@ TravisPusher.prototype.unsubscribe = (channel) ->
   @pusher.unsubscribe(channel) if @pusher?.channel(channel)
 
 TravisPusher.prototype.prefix = (channel) ->
-  if channel.indexOf(config.pusher.channel_prefix) != 0
-    "#{config.pusher.channel_prefix}#{channel}"
+  prefix = config.pusher.channel_prefix || ''
+  if channel.indexOf(prefix) != 0
+    "#{prefix}#{channel}"
   else
     channel