Do not call Session.close_all
Do not call Session.close_all

Do not call Session.close_all as this will close all the Sessions
that exist in memory, including the sessions that are specific to
the application and unrelated to PyPWS.

And here the closing of sessions is already handled by
_LAST_SESSION.close(), so we can just remove the call to
_SESSION_MAKER.close_all.

tomkralidis/pywps,geopython/pywps,bird-house/PyWPS