Let background page instantiate AccountManagers

Remove the need to expose the server url config as a global.

// FREEBIE

js/axolotl_store.js

@@ -123,8 +123,7 @@
             var prekey = new PreKey({id: keyId});
 
             new Promise(function(resolve) {
-                var accountManager = new textsecure.AccountManager(TEXT_SECURE_SERVER_URL);
-                accountManager.refreshPreKeys().then(resolve);
+                getAccountManager().refreshPreKeys().then(resolve);
             });
 
             return new Promise(function(resolve) {

js/background.js

@@ -62,6 +62,12 @@
             return -1;
         }
     };
+    window.getAccountManager = function() {
+        var USERNAME = storage.get('number_id');
+        var PASSWORD = storage.get('password');
+        return new textsecure.AccountManager(SERVER_URL, USERNAME, PASSWORD);
+    };
+
     storage.fetch();
     storage.onready(function() {
         setUnreadCount(storage.get("unreadCount", 0));
@@ -74,8 +80,6 @@
             init(true);
         });
 
-        window.TEXT_SECURE_SERVER_URL = 'https://textsecure-service-staging.whispersystems.org';
-
         if (open) {
             openInbox();
         }

js/options.js

@@ -65,7 +65,7 @@
             $('#init-setup').show().addClass('in');
             $('#status').text("Connecting...");
 
-            var accountManager = new bg.textsecure.AccountManager(bg.TEXT_SECURE_SERVER_URL);
+            var accountManager = new bg.getAccountManager();
             accountManager.registerSecondDevice(setProvisioningUrl, confirmNumber, incrementCounter).then(function() {
                 var launch = function() {
                     bg.openInbox();