Not sending SyncMessage if only linked device

[Schmiddiii]

If using Flare (and thus presage + libsignal-service-rs) as the only linked device to Signal Android/IOS, there is no sync message sent to the main device. I suspect that this line should also check if the device is a secondary device and then always send a SyncMessage.

This was figured out in the Flare Matrix room, at the bottom of this thread.

[rubdos]

I supposed sub_device_count should handle that, but I think you're right. I wonder whether we should (again) change the get_sub_device_sessions semantics, this time to mean: return all device IDs that are not the current device. I'm not sure what Whisperfish takes as semantics there.

[gferon]

Is this still a problem? I tested right now and it works fine.

[Schmiddiii]

Sorry, I forgot to respond to this issue. I sadly cannot currently check (with the current versions of libsignal-service-rs) if this is still an issue due to the contact sync issue of presage and me not wanting to loose my linked devices that I normally use. I will check again once the contact sync issue of presage is resolved.

[Schmiddiii]

Should be fixed by #262