Failure to load deprecated libraries leads to misleading error message for users

This `try : except` leads to a misleading error message if the nested dependency of, say `load_pkcs12`, no longer exists

It seems like the `HAVE_OPENSSL` value
https://github.com/GoogleCloudPlatform/gsutil/blob/a872f98b59bad2bb72010afb9b0b90aa91ec5d0c/gslib/commands/signurl.py#L65

leads to the user error message of `CommandException: The signurl command requires the pyopenssl library (try pip install pyopenssl or easy_install pyopenssl)` which leads to confusion about how to proceed.

Workaround: install the current n-1 version of pyopenssl: `pip3 install pyopenssl==23.2.0` which does indeed work

Test case: `gsutil signurl -d 10m `

Related: https://github.com/GoogleCloudPlatform/gsutil/issues/1753

Start in gslib/commands/signurl.py at the HAVE_OPENSSL check linked in the issue, then run the provided gsutil signurl command with the affected dependency versions. Trace how the nested load_pkcs12 failure becomes the pyopenssl-missing message; done means users receive an accurate actionable error when the deprecated library dependency cannot load.

Written by the indexing model from the issue text.