Retract v3.2.28

The SCTP implementation used in v3.2.28 fails to establish a connection
with other WebRTC implementations. The implementation of ZeroChecksum
assumes incorrectly that the feature is bi-directional

SCTP ZeroChecksum is actually a uni-directional feature which causes the
Assocations to be unable to communicate.

go.mod

@@ -34,3 +34,7 @@ require (
 	golang.org/x/sys v0.18.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+// SCTP ZeroChecksum implementation has a interoperability bug
+// 3.2.28 can only work against itself, not other versions of webrtc
+retract v3.2.28