FIX: mobile setting in Register API

mooctest-site-server/src/main/java/cn/iselab/mooctest/site/web/logic/impl/UserLogicImpl.java

@@ -94,7 +94,6 @@ public class UserLogicImpl extends BaseLogic implements UserLogic {
         User user = userVOWrapper.unwrap(userVO);
         user.setPassword(EncryptionUtil.encryptMD5(userVO.getPassword()));
         user.setCreateTime(new Timestamp(System.currentTimeMillis()));
-        user.setMobile(null);
         return userService.createUser(user);
     }