babeld: 3 more timing statements in config text

This commit makes the following lines visible in running-config text,
when respective intervals are configured to non-default values:

* babel hello-interval
* babel update-interval
* babel resend-delay
diff --git a/babeld/babel_interface.c b/babeld/babel_interface.c
index 00d53bc..958b1b9 100644
--- a/babeld/babel_interface.c
+++ b/babeld/babel_interface.c
@@ -986,6 +986,16 @@
                 vty_out (vty, " babel split-horizon%s", VTY_NEWLINE);
                 write++;
             }
+            if (babel_ifp->hello_interval != BABEL_DEFAULT_HELLO_INTERVAL)
+            {
+                vty_out (vty, " babel hello-interval %u%s", babel_ifp->hello_interval, VTY_NEWLINE);
+                write++;
+            }
+            if (babel_ifp->update_interval != BABEL_DEFAULT_UPDATE_INTERVAL)
+            {
+                vty_out (vty, " babel update-interval %u%s", babel_ifp->update_interval, VTY_NEWLINE);
+                write++;
+            }
         }
         vty_out (vty, "!%s", VTY_NEWLINE);
         write++;