Update dwgpsd.c

[lbartoletti]

Fix build with gpsd 3.20
It's the same issue as #196

https://gitlab.com/gpsd/gpsd/-/blob/release-3.20/gps.h#L78

[lbartoletti]

Fixes #241

Some context, I update gpsd to 3.2.0 and I fix all packages which depends on it https://reviews.freebsd.org/D23920

[wb2osz]

Did you actually try running this?
I tried the same thing and it compiled fine with gpsd 3.2.0 but did not work properly. Messages were not being received from the daemon. I didn't want to release the code change without seeing it work properly first.
I also noticed this in the gps.h revision history:
* mark altitude in gps_fix_t as deprecated and undefined
This seems to mean that more conditional compilation would be needed to use the "altitude" field for for API versions < 9 and some other field (probably altHAE) for API >= 9.
I wasted a lot of time on this about a month ago, got frustrated, and gave up.

[wb2osz]

This is not the same as issue #196.
That was libgps changing the number of arguments for one of the most important functions going from API 6 to 7.

[wb2osz]

Thanks for pointing that out.
Keeping up with all the libgps incompatible API changes is a never ending chore.
Dealing with API 9 was a little more complicated than changing one line.
This should be OK in the recent release 1.6.