Fix date used to retrieve new messages (#265)

Using the conversation read date to check for new messages will retrieve the same message multiple times if the last read date is older than when the new message arrives.  Instead us the last message we have retrieved as the date to check for new messages from.

js/devel/app.js

@@ -16,6 +16,7 @@ var Sms = {
 	unreadCountNotifStep: 12,
 	lastUnreadCountAllConv: 0,
 	lastContactListMsgDate: 0,
+	lastMessageDate: 0,
 	originalTitle: document.title,
 	photoVersion: 1,
 

js/devel/legacy.js

@@ -126,7 +126,7 @@ app.controller('OcSmsController', ['$scope', '$interval', '$timeout', '$compile'
 		$scope.checkNewMessages = function () {
 			Sms.unreadCountAllConv = 0;
 			$.getJSON(Sms.generateURL('/front-api/v1/new_messages'),
-				{'lastDate': Sms.lastContactListMsgDate},
+				{'lastDate': Sms.lastMessageDate},
 				function (jsondata, status) {
 					var bufferedContacts = [];
 
@@ -323,6 +323,7 @@ app.controller('OcSmsController', ['$scope', '$interval', '$timeout', '$compile'
 			});
 
 			Sms.lastContactListMsgDate = jsondata["lastRead"];
+			Sms.lastMessageDate = jsondata["lastMessage"];
 		};
 
 		// Return (int) msgCount, (str) htmlConversation