Don't fail on an empty database

db/migrate/20160902122721_drop_gitorious_field_from_application_settings.rb

@@ -7,11 +7,16 @@ class DropGitoriousFieldFromApplicationSettings < ActiveRecord::Migration
   def up
     require 'yaml'
 
-    yaml =  if Gitlab::Database.postgresql?
-              connection.execute('SELECT import_sources FROM application_settings;').values[0][0]
-            else
-              connection.execute('SELECT import_sources FROM application_settings;').first[0]
-            end
+    import_sources = connection.execute('SELECT import_sources FROM application_settings;')
+
+    yaml = if Gitlab::Database.postgresql?
+             import_sources.values[0][0]
+           else
+             return unless import_sources.first
+
+             import_sources.first[0]
+           end
+
     yaml = YAML.safe_load(yaml)
     yaml.delete 'gitorious'
 

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160902122721) do
+ActiveRecord::Schema.define(version: 20160901141443) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"