explicitly shut down client as well

Signed-off-by: Antoine Toulme <[email protected]>

Author: atoulme

fabric-chaincode-shim/src/test/java/org/hyperledger/fabric/traces/impl/OpenTelemetryTracesProviderTest.java

@@ -193,6 +193,7 @@ public void onCompleted() {
         List<io.opentelemetry.proto.trace.v1.ResourceSpans> spans = fakeTracesCollector.getReceivedSpans();
         assertThat(spans.isEmpty()).isFalse();
 
+        chaincodeSupportClient.shutdown(itm);
         server.shutdown();
     }