eureka: detect _ in the trackerRegex (#4100)
eureka: detect _ in the trackerRegex (#4100)

It's possible for the tracker id to be generated with an underscore.
quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot,quisquous/cactbot