mainview: fix account selection

- avoid duplicate call of LRC's setTopAccount()
- welcome view displays always the first account on the list, so passing the index is not necessary
- conversationsadapter and messagesadapter no longer listen to currentAccountChanged signal since there is a specific function for the setup

Gitlab: #12
Change-Id: Iac932d2596bf59c7528d83be799342ccefeea6b0
diff --git a/src/messagesadapter.cpp b/src/messagesadapter.cpp
index 056286e..5214d0b 100644
--- a/src/messagesadapter.cpp
+++ b/src/messagesadapter.cpp
@@ -39,20 +39,7 @@
 MessagesAdapter::~MessagesAdapter() {}
 
 void
-MessagesAdapter::initQmlObject()
-{
-    connect(&LRCInstance::instance(),
-            &LRCInstance::currentAccountChanged,
-            this,
-            &MessagesAdapter::slotAccountChanged);
-    connectConversationModel();
-}
-
-void
-MessagesAdapter::slotAccountChanged()
-{
-    connectConversationModel();
-}
+MessagesAdapter::initQmlObject() {}
 
 void
 MessagesAdapter::setupChatView(const QString &uid)