fix gps test runner

old-commit-hash: e23a25c3ae

tools/gpstest/run_unittest.sh

@@ -4,7 +4,7 @@
 
 # run limeGPS with random static location
 timeout 300 ./simulate_gps_signal.py 32.7518 -117.1962 &
-gps_PID=$(ps -aux | grep -m 1 "timeout 300" | cut -d ' ' -f 7)
+gps_PID=$(ps -aux | grep -m 1 "timeout 300" | awk '{print $2}')
 
 echo "starting limeGPS..."
 sleep 10