Fix nil pointer access on GetMemberPIDs
Fix nil pointer access on GetMemberPIDs

GetMemberPIDs accesses a nil pointer if the cluster has not
yet been initialized. This is rather inconvenient if unit
tests (that should not need a consul) access the memberList.

AsynkronIT/protoactor-go,rogeralsing/gam,AsynkronIT/gam,AsynkronIT/gam,AsynkronIT/protoactor-go