Do obfs4 settings bridges work better in china and hong knog?

Right now in China in the circumvention map we recommend snowflake, which in user research has being behaving very slow there. And in Hong Kong we don't provide any configuration, so if tor fails to connect TB will try to use the builtin bridges.

Let's configure both countries to use obfs4 settings bridges. We'll wait 10 days after enabling them and see if there is an increase of users and/or complains from them in the support channels.

cc: @gus @duncan