Remove listener.cancel from RestateServerCall::close

Calling listener.cancel is problematic in the Kotlin case because
it terminates the Kotlin coroutine via an exception which will be
caught and triggers outputting the ErrorMessage.

Author: tillrohrmann

sdk-core/src/main/java/dev/restate/sdk/core/RestateServerCall.java

@@ -89,13 +89,12 @@ public void sendMessage(MessageLite message) {
 
   @Override
   public void close(Status status, Metadata trailers) {
+    // Let's close the listener first
+    listener.close();
+
     if (status.isOk() || Util.containsSuspendedException(status.getCause())) {
-      listener.close();
       syscalls.close();
     } else {
-      // Let's cancel the listener first
-      listener.cancel();
-
       if (Util.isTerminalException(status.getCause())) {
         syscalls.writeOutput(
             (TerminalException) status.getCause(),