LdapImpalaShellTest.testShellLdapAuth failed because Python version is too old

The recent build of impala-cdh6.x-exhaustive-centos6-shard1 failed due to a failed test `
org.apache.impala.customcluster.LdapImpalaShellTest.testShellLdapAuth`, which is recently updated due to IMPALA-8828.

According to the error messages provided in the following, it seems that the Python version is too old.

Starting Impala Shell using LDAP-based authentication
Python version too old. SSLContext not supported.
Error connecting: NotImplementedError, 
Not connected to Impala, could not execute queries.
 expected:<0> but was:<1>