Remove call_ip in the SchedulerServer

[yahoNanJing]

Describe the bug

Currently there's a field in the SchedulerServer for recording caller ip which sends requests to the scheduler. However, for one scheduler, there will be multiple clients. Concurrency issue may occur. It's not a good way for record the requester info in a global field. Therefore, it's better to remove it from the SchedulerServer.

We can get the requester ip from the hyper info and set it to the tonic info. Then in each tonic-based grpc interface, we can get the the requester ip from the Request.

[drauschenbach]

Resolved elsewhere. See #1559.

[alamb]

Thanks @drauschenbach