Fix broken build for time_offset in gpsmon

fix broken scons build with the following:
scons minimal=on ncurses=on pps=on socket_export=on

Missing NTP_ENABLE guard around usage of time_offset in gpsmon_hook()

1 files changed, 2 insertions, 0 deletions

diff --git a/gpsmon.c b/gpsmon.c
index b80d4106..563d75dc 100644
--- a/gpsmon.c
+++ b/gpsmon.c
@@ -744,7 +744,9 @@ static void gpsmon_hook(struct gps_device_t *device, gps_mask_t changed UNUSED)
 			      (long)session.gpsdata.toff.real.tv_sec,
 			      (long)session.gpsdata.toff.real.tv_nsec);
 	    /*@+type +noeffect@*/
+#ifdef NTP_ENABLE
 	    time_offset = session.gpsdata.toff;
+#endif /* NTP_ENABLE */
 	    return;
 	}
     } else if (!serial && str_starts_with((char*)device->lexer.outbuffer, "{\"class\":\"PPS\",")) {