Remove a duplicate PDF file from the test suite

The files issue3115.pdf and issue2337.pdf are identical, the only difference being that the first one is an `eq` test and the second one a `load` test. Hence there is no reason to keep the `load` test, since it's just a subset of the `eq` test.
Merge pull request #5235 from Snuffleupagus/remove-duplicate-test-file

Remove a duplicate PDF file from the test suite