title: Config hive with sentry: NullPointerException privilegeObj is null for
body: <p>I've followed <a href="https://www.cloudera.com/documentation/enterprise/5-7-x/topics/sg_sentry_service_config.html#concept_gvl_szm_vq" rel="nofollow">the guide</a> step by step. But error occured when I tried to grant privilege to the role:</p>
  
  <pre><code>0: jdbc:hive2://localhost:10000/&gt; GRANT ALL ON SERVER server1 TO ROLE admin_role;
  Error: Error while compiling statement: FAILED: NullPointerException privilegeObj is null for 
  TOK_GRANT
     TOK_PRIVILEGE_LIST
        TOK_PRIVILEGE
           TOK_PRIV_ALL
     TOK_PRINCIPAL_NAME
        TOK_ROLE
           admin_role
     TOK_PRIV_OBJECT
        TOK_SERVER_TYPE
           server1 (state=42000,code=40000)
  </code></pre>
  
  <p>I'm login to beeline as hive and the password is correct, create role is ok, and i can see the roles：</p>
  
  <pre><code>0: jdbc:hive2://localhost:10000/&gt; show roles;
  +-------------+--+
  |    role     |
  +-------------+--+
  | test        |
  | admin_role  |
  +-------------+--+
  </code></pre>
  
  <p>but I cannot get current roles:</p>
  
  <pre><code>0: jdbc:hive2://localhost:10000/&gt; show current roles;
  +-------+--+
  | role  |
  +-------+--+
  +-------+--+
  </code></pre>