Avoid blocking in SCNetwork from checking reachability too early
Avoid blocking in SCNetwork from checking reachability too early

Don't call SCNetworkReachabilityGetFlags until it's scheduled with the runloop,
else it could block for a long time on a flaky network doing a DNS lookup.
Fixes #156

alfared/couchbase-lite-ios,alfared/couchbase-lite-ios,amco/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,pegli/couchbase-lite-ios,macoscope/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,ryuzmukhametov/couchbase-lite-ios,alfared/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,Chavenay/couchbase-lite-ios,tomco/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,brendand/couchbase-lite-ios,tomco/couchbase-lite-ios,brendand/couchbase-lite-ios,tomco/couchbase-lite-ios,couchbase/couchbase-lite-ios,evsukov89/couchbase-lite-ios,brendand/couchbase-lite-ios,Chavenay/couchbase-lite-ios,macoscope/couchbase-lite-ios,couchbase/couchbase-lite-ios,ryuzmukhametov/couchbase-lite-ios,lordkev/couchbase-lite-ios,jkingyens/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,macoscope/couchbase-lite-ios,pegli/couchbase-lite-ios,ryuzmukhametov/couchbase-lite-ios,couchbase/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,evsukov89/couchbase-lite-ios,pellekrogholt/couchbase-lite-ios,evsukov89/couchbase-lite-ios,jkingyens/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,tomco/couchbase-lite-ios,brendand/couchbase-lite-ios,pegli/couchbase-lite-ios,Chavenay/couchbase-lite-ios,jkingyens/couchbase-lite-ios,pegli/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,mz2/couchbase-lite-ios,macoscope/couchbase-lite-ios,lordkev/couchbase-lite-ios,brendand/couchbase-lite-ios,myDario/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,alfared/couchbase-lite-ios,ipmobiletech/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,mz2/couchbase-lite-ios,myDario/couchbase-lite-ios,couchbase/couchbase-lite-ios,gotmyjobs/couchbase-lite-ios,lordkev/couchbase-lite-ios,lordkev/couchbase-lite-ios,myDario/couchbase-lite-ios,mz2/couchbase-lite-ios,ryuzmukhametov/couchbase-lite-ios,amco/couchbase-lite-ios,jkingyens/couchbase-lite-ios,couchbase/couchbase-lite-ios