[Bugfix] Gracefully handle huggingface hub http error

[ywang96]

Currently if huggingface hub is down, users cannot start the engine because of the following code that always checks against the hub if the specified model has a encoder config, even though the users have all the other files available locally.

vllm/vllm/config.py

Line 299 in f17f1d4

self.encoder_config = self._get_encoder_config()

vllm/vllm/config.py

Lines 417 to 419 in f17f1d4

	def _get_encoder_config(self):
	return get_sentence_transformer_tokenizer_config(
	self.model, self.revision)

This PR gracefully handles the http error from huggingface hub and gives warnings if there's indeed connection issue.

IMO a proper fix for this issue should be optionally calling _get_encoder_config to check against the hub (though I'm not sure there's a good way to do so) cc @flaviabeo @maxdebayser

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[ywang96]

Thanks @charlesfrye for finding out the root cause!

[simon-mo]

non blocking, can we figure out a way to test this? maybe edit /etc/hosts to block huggingface.co to see whether offline mode is truly working

[maxdebayser]

Thanks for fixing this!

[tlrmchlsmth]

🙏 🙏 🙏