autopair: Try a fixed pincode for keyboards rejecting random codes
autopair: Try a fixed pincode for keyboards rejecting random codes

This patch makes the autopair plugin try a fixed "0000" pincode for
keyboards that reject the pincode too fast (less than 500ms). This too
short delay rejecting the pincode means that the user didn't have time
to type the random pincode in the bluetooth keyboard and was the
keyboard who actually rejected it.

pstglia/external-bluetooth-bluez,ComputeCycles/bluez,silent-snowman/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,silent-snowman/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,silent-snowman/bluez,ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,pkarasev3/bluez,ComputeCycles/bluez