Take care if the gpsd API version with gps_read() as function prototype as changed in version 7.

YSFGateway/APRSWriter.cpp

@@ -284,8 +284,14 @@ void CAPRSWriter::sendIdFrameMobile()
 	if (!::gps_waiting(&m_gpsdData, 0))
 		return;
 
+#if GPSD_API_MAJOR_VERSION >= 7
 	if (::gps_read(&m_gpsdData, NULL, 0) <= 0)
 		return;
+#else
+	if (::gps_read(&m_gpsdData) <= 0)
+		return;
+#endif
+
 
 	if (m_gpsdData.status != STATUS_FIX)
 		return;