pimd: Do not display some default values as part of a show run

There is no need to display igmp default values for the query-interval
and the query-max-response-time-dsec

Before change:

!
interface swp4
 description swp4 -> host-212's swp1
 ip igmp
 ip igmp query-interval 125
 ip igmp query-max-response-time-dsec 100
 ip pim ssm
 link-detect
!

After change:
!
interface br1
 ip igmp
 ip pim ssm
 link-detect
!

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
diff --git a/pimd/pim_vty.c b/pimd/pim_vty.c
index 512c0e6..810dbe8 100644
--- a/pimd/pim_vty.c
+++ b/pimd/pim_vty.c
@@ -157,18 +157,24 @@
       }
 
       /* IF ip igmp query-interval */
-      vty_out(vty, " %s %d%s",
-	      PIM_CMD_IP_IGMP_QUERY_INTERVAL,
-	      pim_ifp->igmp_default_query_interval,
-	      VTY_NEWLINE);
-      ++writes;
+      if (pim_ifp->igmp_default_query_interval != IGMP_GENERAL_QUERY_INTERVAL)
+	{
+	  vty_out(vty, " %s %d%s",
+		  PIM_CMD_IP_IGMP_QUERY_INTERVAL,
+		  pim_ifp->igmp_default_query_interval,
+		  VTY_NEWLINE);
+	  ++writes;
+	}
 
       /* IF ip igmp query-max-response-time */
-      vty_out(vty, " %s %d%s",
-	      PIM_CMD_IP_IGMP_QUERY_MAX_RESPONSE_TIME_DSEC,
-	      pim_ifp->igmp_query_max_response_time_dsec,
-	      VTY_NEWLINE);
-      ++writes;
+      if (pim_ifp->igmp_query_max_response_time_dsec != IGMP_QUERY_MAX_RESPONSE_TIME_DSEC)
+	{
+	  vty_out(vty, " %s %d%s",
+		  PIM_CMD_IP_IGMP_QUERY_MAX_RESPONSE_TIME_DSEC,
+		  pim_ifp->igmp_query_max_response_time_dsec,
+		  VTY_NEWLINE);
+	  ++writes;
+	}
 
       /* IF ip igmp join */
       if (pim_ifp->igmp_join_list) {