v4.12.3: OpenTracks

Bugfix:
- Using GPS and IDLE functionality stored coordinates 0.0/0.0 and thus overestimating all statistics (distance >10.000 km). (Introduced in v4.12.0)
- Idle: also trigger if only one location was received.

Regarding the overestimating distance bug: the stored data will not be fixed within OpenTracks.
Recommendation: export the as KML/KMZ and replace the invalid coordinates.