protocol/display: fix interrupted select handling for Python 3.3/3.4
protocol/display: fix interrupted select handling for Python 3.3/3.4

With Python >=3.3, `select.error` is now an instance of OSError.

Note that there was no issue with Python 3.5 as interrupted system
calls are automatically retried.

benoit-pierre/python-xlib,python-xlib/python-xlib,python-xlib/python-xlib,benoit-pierre/python-xlib