Fix an issue with messenger while opening the same tab twice

www/common/common-messenger.js

@@ -853,6 +853,12 @@ define([
 
         var openPadChat = function (data, cb) {
             var channel = data.channel;
+            if (getChannel(channel)) {
+                eachHandler('event', function (f) {
+                    f('PADCHAT_READY', channel);
+                });
+                return void cb();
+            }
             var keys = data.secret && data.secret.keys;
             var cryptKey = keys.viewKeyStr ? Crypto.b64AddSlashes(keys.viewKeyStr) : data.secret.key;
             var encryptor = Crypto.createEncryptor(cryptKey);

www/contacts/messenger-ui.js

@@ -708,6 +708,7 @@ define([
         var onPadChatReady = function (data) {
             var padChat = common.getPadChat();
             if (data !== padChat) { return; }
+            if (state.channels[data]) { return; }
             execCommand('GET_ROOMS', {padChat: data}, function (err, rooms) {
                 if (err) { return void console.error(err); }
                 if (!Array.isArray(rooms) || rooms.length !== 1) {