load_certificate ignores format argument and infers format from file extension

[DieserFelix]

Describe the bug

When loading a certificate from a file using server.load_certificate, the file's extension takes precedence over the format argument.

To Reproduce

Store a certificate in DER encoding in a file certificate.pem. Try to load it using server.load_certificate("certificate.pem", format="der").

Expected behavior

server.load_certificate should not try to infer the certificate's format from the file's extension if the format argument is provided.

Screenshots

Version

Python-Version: 3.11.6

opcua-asyncio Version (e.g. master branch, 0.9): 1.1.8