increase concurrent attempted connections to 64
increase concurrent attempted connections to 64

Previously this was 32, but due to the way sunspec and solarapi
was probed simultaneously it ended up effectively at 64. Not
compensating for that essentially halved our scan speed.

victronenergy/dbus-fronius,victronenergy/dbus-fronius,victronenergy/dbus-fronius,victronenergy/dbus-fronius