When a router with a route target RT_MIN is detected, we should first update the links from router to that route-target, and then delete it.

Change-Id: Id0f117efef22b0b62944794fd26665f761b39b29
Closes-Bug:1364595
Merge "When a router with a route target RT_MIN is detected, we should first update the links from router to that route-target, and then delete it." into R1.10