Auto merge of #1529 - jtgeibel:update/openssl, r=sgrif

Remove dependencies on openssl 0.9

After recently updating to Ubuntu 18.10, I ran into the issue that `openssl 0.9` doesn't support OpenSSL 1.1.1. Fortunately `openssl 0.10` is already compatible.  This PR bumps our direct dependency on `openssl`.  It also bumps `hyper-tls` and `lettre` to update their transitive dependencies on `openssl`.

It is possible to build against a custom (non-system) version of OpenSSL, which is what I'm doing for now.  I can help with that if anyone else runs into this issue before this is merged.

Author: bors