Improve onos-diagnostics adding sr-mcast-leader

Change-Id: I57e058956a2fd8c4397c97e993851029967e5df5
(cherry picked from commit 160880a18536d464d10d4f2ad8e38581e9ea3e3d)
diff --git a/tools/package/runtime/bin/onos-diagnostics b/tools/package/runtime/bin/onos-diagnostics
index ee610d1..9cc77e3 100755
--- a/tools/package/runtime/bin/onos-diagnostics
+++ b/tools/package/runtime/bin/onos-diagnostics
@@ -97,6 +97,7 @@
     "sr-link-state"
     "sr-mcast-next"
     "sr-mcast-tree"
+    "sr-mcast-leader"
     "sr-next-hops"
     "sr-pw-list"
     "dhcp-relay"