Don't require backports.ssl_match_hostname on Python 2.7.9 and newer

Don't require backports.ssl_match_hostname on Python 2.7.9 and newer

As Python 3.2 support was dropped one can check 2.7.x dependency only.

Tornado running on Python 2.7.9+ doesn't need this backported package,
but some Python packages like circus check package dependencies at
runtime and insist on having backports.ssl_match_hostname installed,
though they don't even use this particular feature.

So checking for exact version makes life of package maintainer easier
especially on embedded Linux distributions like Buildroot.