Fix some edge cases in handling ssl information from PROXY protocol

[prefiks]

When we fail to parse name of cipher suite from PROXY protocol
just say that no ssl is used, instead of trying to fill that
with data from connection between proxy and our server.

This is addressing recent comments from pull request 3175

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[michaelklishin]

Backported to v3.9.x for 3.9.6.

[michaelklishin]

Backported to v3.8.x for 3.8.23.