Update UnknownServiceHandler comment to be clearer about interceptor behavior (#1566)

diff --git a/server.go b/server.go
index bcaaa7d..7c882db 100644
--- a/server.go
+++ b/server.go
@@ -278,7 +278,7 @@
 // handler that will be invoked instead of returning the "unimplemented" gRPC
 // error whenever a request is received for an unregistered service or method.
 // The handling function has full access to the Context of the request and the
-// stream, and the invocation passes through interceptors.
+// stream, and the invocation bypasses interceptors.
 func UnknownServiceHandler(streamHandler StreamHandler) ServerOption {
 	return func(o *options) {
 		o.unknownStreamDesc = &StreamDesc{