Support upgrading OS X: indexer config is incorrect when "upgrading" from 4.0 to 4.5

[ns_server:error,2016-04-05T13:14:04.451+01:00,ns_1@127.0.0.1:index_stats_collector-index<0.413.0>:index_rest:get_json:42]Request to (indexer) http://127.0.0.1:9102/stats?async=true failed: {error,

                                                                     {econnrefused,

                                                                      [{lhttpc_client,

                                                                        send_request,

                                                                        1,

                                                                        [{file,

                                                                          "/Users/jenkins/jenkins/workspace/watson-unix/couchdb/src/lhttpc/lhttpc_client.erl"},

                                                                         {line,

                                                                          220}]},

                                                                       {lhttpc_client,

                                                                        execute,

                                                                        9,

                                                                        [{file,

                                                                          "/Users/jenkins/jenkins/workspace/watson-unix/couchdb/src/lhttpc/lhttpc_client.erl"},

                                                                         {line,

                                                                          169}]},

                                                                       {lhttpc_client,

                                                                        request,

                                                                        9,

                                                                        [{file,

                                                                          "/Users/jenkins/jenkins/workspace/watson-unix/couchdb/src/lhttpc/lhttpc_client.erl"},

                                                                         {line,

                                                                          92}]}]}}