optimize schedulis returns empty ResponseBody (ResponseBody is null )

Author: chenwendong 01013

dss-appconn/appconns/dss-schedulis-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/schedulis/utils/SchedulisHttpUtils.java

@@ -24,6 +24,7 @@
 import com.webank.wedatasphere.dss.standard.app.sso.request.SSORequestOperation;
 import com.webank.wedatasphere.dss.standard.common.exception.operation.ExternalOperationFailedException;
 import com.webank.wedatasphere.dss.standard.sso.utils.SSOHelper;
+import org.apache.commons.lang.StringUtils;
 import org.apache.linkis.httpclient.request.HttpAction;
 import org.apache.linkis.httpclient.response.HttpResult;
 import org.slf4j.Logger;