Simplify the building session on first message code

app/widgets/Chat/chat.js

@@ -191,9 +191,15 @@ var Chat = {
                 };
 
                 if (textarea.dataset.encryptedstate == 'build') {
-                    if (!ChatOmemo.buildMissingSessions(jid)) {
-                        Chat.failedMessage();
-                    }
+                    var store = new ChatOmemoStorage();
+                    store.getLocalRegistrationId().then(deviceId => {
+                        if (deviceId) {
+                            ChatOmemo_ajaxGetMissingSessions(jid, deviceId);
+                        } else {
+                            Chat.disableSending();
+                            ChatOmemo.generateBundle();
+                        }
+                    });
                 } else if (textarea.dataset.encryptedstate == 'yes') {
                     // Try to encrypt the message
                     let omemo = ChatOmemo.encrypt(jid, text);

app/widgets/ChatOmemo/chatomemo.js

@@ -307,17 +307,6 @@ var ChatOmemo = {
             return result;
         });
     },
-    buildMissingSessions: function (jid) {
-        var store = new ChatOmemoStorage();
-        store.getLocalRegistrationId().then(deviceId => {
-            if (deviceId) {
-                ChatOmemo_ajaxGetMissingSessions(jid, deviceId);
-            } else {
-                ChatOmemo.generateBundle();
-                return false;
-            }
-        });
-    },
     encryptDevice: function (plaintext, jid, deviceId) {
         var address = new libsignal.SignalProtocolAddress(jid, parseInt(deviceId, 10));
         var store = new ChatOmemoStorage();