bpo-41182 selector: use DefaultSelector based upon implementation (GH-21257)

On some platform such as VMware ESXi, DefaultSelector fails
to detect selector due to default value.
This fix adds a check and uses the correct selector depending upon
select implementation and actual call.

Fixes: [bpo-41182]()

Signed-off-by: Abhijeet Kasurde <akasurde@redhat.com>