Riak 2.1 needs `{check_crl,true}` in Riak API if HTTPS is enabled [JIRA: RIAK-2307]

[angrycub]

When a user brought their app.config from a 1.4.x install into a Riak 2.1.1 installation, their nodes would not start with the following error:

{"Kernel pid terminated",application_controller,"{application_start_failure,riak_api,{{shutdown,{failed_to_start_child,\"https://xxx.xxx.xxx.xxx:yyyy\",{options,{cacertfile,[]}}}},{riak_api_app,start,[normal,[]]}}}"}

adding the {check_crl,true} tuple to the riak_api proplist in the app.config allowed the node to start properly. Should this be defaulted to something so that nodes with migrated app.config files will not fail to start?