API does not work for enterprise subdomain xxx.datadoghq.com

[asaravindkumar]

Describe the bug
When we use the client with enterprise datadog, which is typically https://.datadoghq.com, there is an error that states "Error calling : the variable site in the server URL has invalid value https://xxx.datadoghq.com. Must be [ ]

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severity/medium

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To Reproduce
Steps to reproduce the behavior:
The error is reproducable by using DD_SITE as some abcd.datadoghq.com.

Expected behavior
API should support all datadoghq.com sites.

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Environment and Versions (please complete the following information):
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Additional context
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