babeld: Fix typo in hello interval command.
diff --git a/babeld/babel_interface.c b/babeld/babel_interface.c
index fafe009..a874289 100644
--- a/babeld/babel_interface.c
+++ b/babeld/babel_interface.c
@@ -430,7 +430,7 @@
     struct interface *ifp;
     babel_interface_nfo *babel_ifp;
 
-    int interval = atoi(argv[1]);
+    int interval = atoi(argv[0]);
 
     ifp = vty->index;
     babel_ifp = babel_get_if_nfo(ifp);