gatt: Remove reading Service Changed characteristic after connected
gatt: Remove reading Service Changed characteristic after connected

Service Changed characteristic is a control-point attribute thus it
cannot be read and attempting to do so will fail. Instead, server shall
send indication once enabled in CCC.

This change is due to "Erratum 3833 - Service Changed" (ESR05) which
changed characteristic value properties from 0x26 to 0x20.

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