[FIX] mail: load more messages

The feature has been broken by rev. 02ec09cb1.

addons/mail/static/src/js/services/chat_manager.js

@@ -396,7 +396,7 @@ var ChatManager =  AbstractService.extend({
      * @param  {integer|string} [options.channelID]
      * @param  {Array} [options.domain]
      * @param  {integer[]} [options.ids]
-     * @param  {boolean} [options.load_more]
+     * @param  {boolean} [options.loadMore]
      * @param  {string} [options.model]
      * @param  {integer} [options.res_id]
      * @return {$.Promise<Object[]>} list of messages
@@ -405,8 +405,8 @@ var ChatManager =  AbstractService.extend({
         var channel;
         var self = this;
 
-        if ('channelID' in options && options.load_more) {
-            // get channel messages, force load_more
+        if ('channelID' in options && options.loadMore) {
+            // get channel messages, force load more
             channel = this.getChannel(options.channelID);
             return this._fetchFromChannel(channel, {domain: options.domain || {}, loadMore: true});
         }
@@ -1027,7 +1027,7 @@ var ChatManager =  AbstractService.extend({
      * @param  {integer|string} channel.id string for static channels, e.g. 'channel_inbox'
      * @param  {Object} [option={}]
      * @param  {Array} [options.domain] filter on the messages of the channel
-     * @param  {boolean} [options.load_more] Whether it should load more message
+     * @param  {boolean} [options.loadMore] Whether it should load more message
      * @return {$.Promise<Object[]>} resolved with list of messages
      */
     _fetchFromChannel: function (channel, options) {