OUT-795: Disable all sync channels on startup and enable for individual accounts

ThisAddIn.cs

@@ -718,6 +718,9 @@ namespace pEp
                 {
                     Log.Warning("RegisterMyself: Engine returned exception, " + ex.ToString());
                 }
+
+                // Enable Sync if necessary
+                acctSettings.SignalSyncSettingsToEngine();
             }
             else
             {
@@ -2243,6 +2246,9 @@ namespace pEp
             Log.Info("ThisAddIn_Startup: Connect Events");
             Globals.ConnectEvents(true);
 
+            // Disable Sync for all identities (will be enabled later per account)
+            AdapterExtensions.ExecuteWithPassphraseCheck(ThisAddIn.PEPEngine.DisableAllSyncChannels);
+
             /* Sync accounts list. This must be done before RegisterMyself()
              * to be able to set the not for sync flag if necessary.
              */