deleteofflinecollectors always logs an error

[rjury-sumo]

this block of code should not have [ERROR] for both branches of the if as it causes misleading responses when the script is run.

    if r.status_code != 200 and r.status_code != 201:
        log('[ERROR] Failed to delete offline Collectors')
    else:
        log('[ERROR] Successfully deleted offline Collectors')

[rjury-sumo]

suggested fix to also include better error reporting in line with other parts of the code.

    if r.status_code != 200 and r.status_code != 201:
        log('[ERROR] Failed to delete offline Collectors')
        log('[ERROR] %s' % r.json()['message'].lower()[:-1])
    else:
        log('Successfully deleted offline Collectors')