Leave nil if push option parsed but unrecognized

For whatever reason. Do not override with .disabled when not
necessarily intended.

TunnelKit/Sources/Core/SessionProxy+PushReply.swift

@@ -384,7 +384,7 @@ extension SessionProxy {
                     compressionFraming = .compress
                     
                 default:
-                    compressionFraming = .disabled
+                    break
                 }
             }