Describe the bug
Since version 1.7.0, it is not possible to create a scan (sc.scans.create method) with max_time 0 (unlimited). The PyTenable library does not convert it to the value "unlimited" as it was done before.

To Reproduce
Steps to reproduce the behavior:
Create a scan, using the sc.scans.create API with a max_time of 0.

Expected behavior
We expect the scan to be created with the Max Scan Time configured to Unlimited

Screenshots
Response received from Security Center:
{"type":"regular","response":"","error_code":146,"error_msg":"The attribute 'maxScanTime' contains the value '0'. It should be between 1 to 120 hours and sent in seconds or 'unlimited'.\n","warnings":[],"timestamp":1739910455}

System Information (please complete the following information):
Security Center version 6.4.0

Additional context
Add any other context about the problem here.