[Brightbox] Reuses connection for image selection

Fixes #1214 - Server initialisation failed unless you had a configuration
file because it tried to create a second connection directly using the
config details.

We now get access to the 'connection' that exists and use that so it is
already configured and authenticated.

lib/fog/brightbox/compute.rb

@@ -209,7 +209,7 @@ module Fog
         def select_default_image
           return @default_image_id unless @default_image_id.nil?
 
-          all_images = Fog::Compute[:brightbox].list_images
+          all_images = list_images
           official_images = all_images.select {|img| img["official"] == true}
           ubuntu_lts_images = official_images.select {|img| img["name"] =~ /Ubuntu.*LTS/}
           ubuntu_lts_i686_images = ubuntu_lts_images.select {|img| img["arch"] == "i686"}

lib/fog/brightbox/models/compute/server.rb

@@ -38,8 +38,10 @@ module Fog
         attribute :server_type
 
         def initialize(attributes={})
-          self.image_id ||= Fog::Compute[:brightbox].default_image
+          # Call super first to initialize the 'connection' object for our default image
           super
+          # FIXME connection is actually <Fog::Compute::Brightbox::Real> not <Fog::Connection>
+          self.image_id ||= connection.default_image
         end
 
         def zone_id