fix-6316 (#6317)

dolphinscheduler-server/src/main/resources/config/install_config.conf

@@ -98,8 +98,8 @@ hdfsRootUser="hdfs"
 kerberosStartUp="false"
 # kdc krb5 config file path
 krb5ConfPath="$installPath/conf/krb5.conf"
-# keytab username
-keytabUserName="hdfs-mycluster@ESZ.COM"
+# keytab username,watch out the @ sign should followd by \\
+keytabUserName="hdfs-mycluster\\@ESZ.COM"
 # username keytab path
 keytabPath="$installPath/conf/hdfs.headless.keytab"
 # kerberos expire time, the unit is hour