Added logs

added username log if unable to authenticate
newly created user for 1st time while its
account is still inactive.
Purpose of log is to find specific useranme
inorder to investigagte LERANER-6026

common/djangoapps/student/helpers.py

@@ -415,6 +415,8 @@ def authenticate_new_user(request, username, password):
     password = normalize_password(password)
     backend = load_backend(NEW_USER_AUTH_BACKEND)
     user = backend.authenticate(request=request, username=username, password=password)
+    if not user:
+        log.warning("Unable to authenticate user: {username}".format(username=username))
     user.backend = NEW_USER_AUTH_BACKEND
     return user