smux: adjust read after close behavior
smux: adjust read after close behavior

MrStrong/Sia,NebulousLabs/Sia,mtlynch/Sia,ericflo/Sia,MrStrong/Sia,ericflo/Sia,NebulousLabs/Sia,mharkus/Sia,ChrisSchinnerl/Sia,ChrisSchinnerl/Sia,mharkus/Sia,mtlynch/Sia