This fixes (or at least works around) a race condition where the
`status_flags.condition_local_position_valid` is still `false` but the
`status_flags.condition_global_position_valid` is already `true`.
The way to reproduce it is t:
1. Poll home position to check if home is initialized
2. Send arm and takeoff command as soon as home is initialized
Then arming will succeed but takeoff will fail because there is a check
for `status_flags.condition_local_position_valid` in
`main_state_transition()` to enter TAKEOFF.
ee6a79279f