reset Attachment.storage_path at the end of attachment tests

Attachment files are deleted when database data were deleted.
So, other tests fail.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@7911 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/attachment_test.rb

@@ -141,5 +141,7 @@ class AttachmentTest < ActiveSupport::TestCase
     assert_equal 17, la1.id
     la2 = Attachment.latest_attach([a1, a2], "Testfile.PNG")
     assert_equal 17, la2.id
+
+    set_tmp_attachments_directory
   end
 end