consul server: Missing check 'serfHealth' registration

Consul server continuously reports the following error:
```
[ERR] http: Request PUT /v1/session/create, error: rpc error making call: Missing check 'serfHealth' registration
...
```
it can't recover until it restart.
According to the code, I don't know why `reconcilemember` didn't execute successfully

### Consul info for both Client and Server

consul version: 1.6.2

Start with the Consul server path handling PUT /v1/session/create and trace how the missing serfHealth registration is reported. Read the reconcilemember logic mentioned in the issue and follow the registration lifecycle around server membership. Done means the reported condition can be reproduced and the server recovers without requiring a restart.

Written by the indexing model from the issue text.