fixes after more import testing

lib/gitlab/bitbucket_import/client.rb

@@ -6,7 +6,7 @@ module Gitlab
       attr_reader :consumer, :api
 
       def self.from_project(project)
-        credentials = project.import_data.credentials if project.import_data
+        credentials = project.import_data.stringified_credentials if project.import_data
         if defined?(credentials) && credentials['bb_session']
           token = credentials['bb_session']['bitbucket_access_token']
           token_secret = credentials['bb_session']['bitbucket_access_token_secret']

lib/gitlab/gitlab_import/importer.rb

@@ -5,7 +5,7 @@ module Gitlab
 
       def initialize(project)
         @project = project
-        credentials = import_data.credentials
+        credentials = import_data.stringified_credentials
         if credentials && credentials["password"]
           @client = Client.new(credentials["password"])
           @formatter = Gitlab::ImportFormatter.new