fix for single host config

lib/blockchainexplorers/insight.js

@@ -155,7 +155,7 @@ Insight.prototype.estimateFee = function(nbBlocks, cb) {
 Insight.prototype.initSocket = function() {
 
   // sockets always use the first server on the pull
-  var socket = io.connect(this.hosts[0], {
+  var socket = io.connect(_.first([].concat(this.hosts)), {
     'reconnection': true,
   });
   return socket;