pa-tests: Add more info to connector test error
pa-tests: Add more info to connector test error

Summary:
Connector tests have failed intermittently in automation with the
could not get connector from json output message.  This adds the output text
to the error message to be able to gather more information about the
error if it occurs again.

Test Plan: make lint

Reviewers: cwallin, anton

Reviewed By: cwallin, anton

Subscribers: anu

Differential Revision: https://phabricator.td.teradata.com/D732

prestodb/presto-admin,Svjard/presto-admin,Svjard/presto-admin,prestodb/presto-admin