Fix an action of t3-troubleshot-mcast command when no sink for a multicast route

- Prints a message saying that there is no sink to trace

Change-Id: Ib113170c2c2a73e8a71b3819d2b814113adf357d
(cherry picked from commit fbd65dbd60d20878a3576de1fbd68d4bdee6f26c)
2 files changed
tree: 476ea9715af30b364cb6c68e653f59ecdacba00c
  1. BUILD
  2. app/
  3. web/