TRUNK-6693: Switch Argon2 config from global to runtime properties

Author: Juliet wamalwa

api/src/main/java/org/openmrs/api/db/hibernate/HibernateUserDAO.java

@@ -484,6 +484,9 @@ public boolean isSecretAnswer(User u, String answer) throws DAOException {
 
 		LoginCredential credentials = getLoginCredential(u);
 		String answerOnRecord = credentials.getSecretAnswer();
+		if (StringUtils.isEmpty(answerOnRecord)) {
+			return false;
+		}
 		return Security.hashMatches(answerOnRecord, answer.toLowerCase() + credentials.getSalt());
 	}