Workaround Empty Forts

[loklam]

Short Description: Sometimes, the API return empty forts. This causes move_to_fort fail. To workaround this, return prev forts, if API return empty forts.

Fixes:

[Sammy-L]

I've tested this code. It works very well. Niantic changed the search respond rate to about 4s since last patch. So the fort scan nearly always return empty result. Saving the old result does help for situations while server refuse to give response.

[kloz8879]

I Have also tested this and it works great! Thank you.

[loklam]

This has been fixed at #2269