Update SymphonyBdkTestMock.java

Author: symphony-enrico

symphony-bdk-test/symphony-bdk-test-jupiter/src/main/java/com/symphony/bdk/test/SymphonyBdkTestMock.java

@@ -47,6 +47,10 @@ public class SymphonyBdkTestMock {
   @Data
   private static class MockDatafeedLoop implements DatafeedLoop {
 
+    public MockDatafeedLoop() {
+      SymphonyBdkTestUtils.clearListeners();
+    }
+
     @Override
     public void start() {
     }