virNetServerClientGetInfo returns the client's remote address
as a string, which is a part of the client object.
Use VIR_STRDUP to make a copy which can be freely accessed
even after the virNetServerClient object is unlocked.
To reproduce, put a sleep between virObjectUnlock in
virNetServerClientGetInfo and virTypedParamsAddString in
adminClientGetInfo, then close the queried connection during
that sleep.
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