[pinpoint-apm#11497] Fix potential NPE

agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/receiver/grpc/ActiveThreadCountStreamSocket.java

@@ -75,7 +75,7 @@ public void close() {
 
     @Override
     public void close(Throwable throwable) {
-        logger.warn("close. message:{}", throwable.getMessage(), throwable);
+        logger.warn("close", throwable);
         close0(throwable);
     }
 

agent-module/profiler/src/test/java/com/navercorp/pinpoint/profiler/receiver/grpc/ActiveThreadCountStreamSocketTest.java

@@ -0,0 +1,24 @@
+package com.navercorp.pinpoint.profiler.receiver.grpc;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.mockito.Mockito.mock;
+
+class ActiveThreadCountStreamSocketTest {
+
+    @Test
+    void close_NPE() {
+        GrpcStreamService grpcStreamService = mock(GrpcStreamService.class);
+        ActiveThreadCountStreamSocket socket = new ActiveThreadCountStreamSocket(1, grpcStreamService);
+        socket.close(null);
+    }
+
+    @Test
+    void close() {
+        GrpcStreamService grpcStreamService = mock(GrpcStreamService.class);
+        ActiveThreadCountStreamSocket socket = new ActiveThreadCountStreamSocket(1, grpcStreamService);
+        socket.close(new IOException("test"));
+    }
+}