Description of problem:

Unable to execute remote execution job for ansible-playbook if the ssh user value is set during the job and removed the user value from Administer -> Settings ->  Remote execution -> ssh user

Version-Release number of selected component (if applicable):

Red Hat Satellite 6.13.

How reproducible:

Always

Steps to Reproduce:

1. Remove the ssh user value from Administer -> Settings -> Remote execution tab.

2. Select the host to schedule remote exection job.

3. Select Job Catagory as Ansible Playbook and Job template as Ansible Roles - Ansible Default.

4. Under Advanced fields put value of ssh user for example: rexuser and run the job.

Actual results:

- The job fails with below error:

~~~
fatal: [satellite.example.com]: UNREACHABLE! => {"changed": false, "msg": "Invalid/incorrect password: \n\nPermission denied, please try again.", "unreachable": true}
~~~


Expected results:

- The job should execute successfully.

Additional info:

- If we set the ssh user value in Administer -> Settings -> Remote execution -> SSH User, for example, rexuser then the task is completed successfully.