ui: Again fix issue with conversations not loading

Again: If we receive a message before first loading a
conversation, it won't load it on open.

lib/redux/conversation/middlewares.dart

@@ -19,12 +19,10 @@ void conversationMiddleware(Store<MoxxyState> store, action, NextDispatcher next
         "jid": args.jid
     });
 
-    if (!store.state.messages.containsKey(args.jid)) {
-      FlutterBackgroundService().sendData({
-          "type": "LoadMessagesForJidAction",
-          "jid": args.jid
-      });
-    }
+    FlutterBackgroundService().sendData({
+        "type": "LoadMessagesForJidAction",
+        "jid": args.jid
+    });
   } else if (action is SetOpenConversationAction) {
     FlutterBackgroundService().sendData({
         "type": "SetCurrentlyOpenChatAction",

lib/repositories/database.dart

@@ -83,6 +83,16 @@ class DatabaseRepository {
 
   /// Loads all messages for the conversation with jid [jid].
   Future<void> loadMessagesForJid(String jid) async {
+    if (this.loadedConversations.indexOf(jid) != -1) {
+      this.sendData({
+          "type": "LoadMessagesForJidResult",
+          "jid": jid,
+          "messages": this._messageCache[jid]!.map((m) => m.toJson()).toList()
+      });
+     
+      return;
+    }
+
     final messages = await this.isar.dBMessages.where().conversationJidEqualTo(jid).findAll();
     this.loadedConversations.add(jid);