SNI_server_name is deprecated

[flip111]

while getting https://groups.google.com/forum/feed/elm-discuss/msgs/atom.xml?num=50 i get this:

Error executing request: exception 'UnexpectedValueException' with message 'Unable to complete SSL/TLS handshake: SNI_server_name is deprecated in favor of peer_name' in vendor\react\socket-client\src\StreamEncryption.php:108

I'm not using this library directly but as a dependency of https://github.com/phergie/phergie-irc-plugin-react-feedticker

[clue]

Thanks for reporting @flip111. This (only) happens in PHP 5.6+, see also composer/composer#2887.

I'll look into filing a PR to fix this and add a test case.