mission file open: Cant save plans with *.waypoints extensions but can parse them

[dkati]

Many of us may use mission planner for flight. Although i personally use QGC for my flights and i would like to import/export my plans on both softwares for my students

Steps to Reproduce:

1. Open a plan with *.waypoints extension
2. save it as ...
3. You cant save it as waypoints

System Information

Operating System: Windows10

• QGC Dev version: HEAD:916f9938e 2019-11-30 20:35:03 +0000 QGC build: daily Flight Controller: doesnt matter Autopilot (with version): doesnt matter