Fixed random test fail in test close database
Fixed random test fail in test close database

Instead of using keyValueObservingExpectationForObject which sometimes has an issue throwing an exception as cannot unregister the observer, fall back to use the old run-loop checking style.

couchbase/couchbase-lite-ios,tomco/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,alfared/couchbase-lite-ios,tomco/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,lordkev/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,amco/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,tomco/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,brendand/couchbase-lite-ios,amco/couchbase-lite-ios,brendand/couchbase-lite-ios,alfared/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,amco/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,alfared/couchbase-lite-ios,tomco/couchbase-lite-ios,amco/couchbase-lite-ios,alfared/couchbase-lite-ios,lordkev/couchbase-lite-ios,couchbase/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,lordkev/couchbase-lite-ios,brendand/couchbase-lite-ios,amco/couchbase-lite-ios,lordkev/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios