Julian Oes c15d3f7cfa mavsdk_tests: retry gz model spawn command
This should help when gzserver does not respond yet and we end up
without a model and hence can't connect later and time out.

This change also required a fix to prevent the tester to hang on
terminating all runners. By using poll instead of only read we can
prevent that and actually properly join the logger thread.
2021-12-02 11:40:26 -05:00
..
2019-10-14 10:53:13 -04:00