[ Reason ]
Fix Bug #1031059 (FTBFS due to flaky test)

[ Impact ]
Some people may not be able to build the package without errors.

[ Tests ]
I've checked that the package builds ok on the systems where it used to fail.

[ Risks ]
Very low. No real code changes, we are just skipping a flaky test.

[ Checklist ]
   [X] *all* changes are documented in the d/changelog
   [X] I reviewed all changes and I approve them
   [X] attach debdiff against the package in (old)stable
   [X] the issue is verified as fixed in unstable

[ Changes ]
See changelog.

[ Other info ]
Change is trivial so I'm uploading next.