Always use HTTP handshaking in overlay:

Inbound and outbound peer connections always use HTTP handshakes to
negotiate connections, instead of the deprecated TMHello protocol
message.

rippled versions 0.27.0 and later support both optional HTTP handshakes
and legacy TMHello messages, so always using HTTP handshakes should not
cause disruption. However, versions before 0.27.0 will no longer be
able to participate in the overlay network - support for handshaking
via the TMHello message is removed.

src/ripple/server/impl/ServerHandlerImp.cpp

@@ -106,17 +106,6 @@ ServerHandlerImp::onAccept (HTTP::Session& session,
     return true;
 }
 
-void
-ServerHandlerImp::onLegacyPeerHello (
-    std::unique_ptr<beast::asio::ssl_bundle>&& ssl_bundle,
-        boost::asio::const_buffer buffer,
-            boost::asio::ip::tcp::endpoint remote_address)
-{
-    // VFALCO TODO Inject Overlay
-    getApp().overlay().onLegacyPeerHello(std::move(ssl_bundle),
-        buffer, remote_address);
-}
-
 auto
 ServerHandlerImp::onHandoff (HTTP::Session& session,
     std::unique_ptr <beast::asio::ssl_bundle>&& bundle,