Adjust a test in php.test for issue #87994

One of the php module tests has a lack of robustness that causes us to have to improve it in issue #87994: Quit clobbering people's work when they click the filter tips link. The test is for whether or not the word 'print' appears on a node edit form, and our use of a modal dialog for input format info causes the word 'print' to be on that form.

I just want this adjustment to get committed so we can stop dealing with it in the other issue. It's been reviewed and set to RTBC many times as a part of that patch, so I'm just setting to RTBC.