fixed a bug in privkeys export

assets/scripts/walletsettings.js

@@ -66,7 +66,7 @@ var WalletSettings = function() {
 											var EncryptWalletDataOutput = JSON.parse(data);
 
 											console.log(EncryptWalletDataOutput[wifkey_coin_handle + 'wif']);
-											WifKeyDivContent += '<table class="table">';
+											var WifKeyDivContent = '<table class="table">' +
 																							'<tr>' +
 																								'<td style="width: 5%">' +
 																									'<b>' + wifkey_coin_handle + '</b>' +