Fix typo in migration test. Closes #11105 [h-lame]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8873 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/test/cases/migration_test.rb

@@ -446,7 +446,7 @@ def test_rename_column_with_an_index
         table.column :hat_name, :string, :limit => 100
         table.column :hat_size, :integer
       end
-      Person.connection.add_index :people, :first_name
+      Person.connection.add_index :hats, :hat_name
       assert_nothing_raised do
         Person.connection.rename_column "hats", "hat_name", "name"
       end