Correction to my MRTG program for GPSD

[David Taylor]

I've corrected a program which I understand may have been referred to in the 
GPS distribution.  Previously I was only looping on satellites, but only up to 
the number used.  I should have been looking at all the visible satellites and 
measuring those which were used.  I recall Gary noting that my SNR values were 
lower than expected.  This change resolves that issue.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      for(i=0;i<=used;i++) {

      for(i=0;i<visible;i++) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The update has been added to my Web page at:

  https://www.satsignal.eu/raspberry-pi/monitoring.html#gps

I'm unsure what else I may need to do.

I tested on a number of Raspberry Pi versions, but some other updates outside 
gpsd mean that gcc can't find lgps, and running install libgps-dev didn't 
resolve the error, and on another the installer couldn't find libgps-dev as the 
OS was too different.  I've not chased these issues any further.

Thanks,
David
--
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