attrib-server: Fix sending "not supported" for indications/notifications
attrib-server: Fix sending "not supported" for indications/notifications

Now that our Attribute Client is able to handle notifications and
indications we don't need to respond that they are not supported.

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