JAVA-2044: In DefaultServerMonitor reset currentException to null each time through the loop. This will ensure that a successful connection after a failed connection will be properly logged.

Author: jyemin

driver-core/src/main/com/mongodb/connection/DefaultServerMonitor.java

@@ -120,6 +120,7 @@ public synchronized void run() {
                 while (!monitorIsClosed) {
                     ServerDescription previousServerDescription = currentServerDescription;
                     Throwable previousException = currentException;
+                    currentException = null;
                     try {
                         if (connection == null) {
                             connection = internalConnectionFactory.create(serverId);