Move connect_cb() upper in attrib/client.c
Move connect_cb() upper in attrib/client.c

This callback will also be used for the watcher implementation, so
moving it avoids a forward declaration.

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