add uniq to insight queries

lib/blockchainexplorers/insight.js

@@ -57,7 +57,7 @@ Insight.prototype.getUtxos = function(addresses, cb) {
     method: 'POST',
     path: this.apiPrefix + '/addrs/utxo',
     json: {
-      addrs: [].concat(addresses).join(',')
+      addrs: _.uniq([].concat(addresses)).join(',')
     },
   };
 
@@ -116,7 +116,7 @@ Insight.prototype.getTransactions = function(addresses, from, to, cb) {
     method: 'POST',
     path: this.apiPrefix + '/addrs/txs' + (qs.length > 0 ? '?' + qs.join('&') : ''),
     json: {
-      addrs: [].concat(addresses).join(',')
+      addrs: _.uniq([].concat(addresses)).join(',')
     },
     timeout: 120000,
   };