Update MyXQL ssl docs (#620)

lib/ecto/adapters/myxql.ex

@@ -22,7 +22,9 @@ defmodule Ecto.Adapters.MyXQL do
     * `:database` - the database to connect to
     * `:pool` - The connection pool module, may be set to `Ecto.Adapters.SQL.Sandbox`
     * `:ssl` - Set to true if ssl should be used (default: false)
-    * `:ssl_opts` - A list of ssl options, see Erlang's `ssl` docs
+    * `:ssl` - Accepts a list of options to enable TLS for the client connection,
+      or `false` to disable it. See the documentation for [Erlang's `ssl` module](`e:ssl:ssl`)
+      for a list of options (default: false)
     * `:connect_timeout` - The timeout for establishing new connections (default: 5000)
     * `:cli_protocol` - The protocol used for the mysql client connection (default: `"tcp"`).
       This option is only used for `mix ecto.load` and `mix ecto.dump`,