Fix syncer logout alert (#5936)

* call self.displayError

* Revert "call self.displayError"

This reverts commit 5d599aa9795f9d816c55378ab6df0a1a691ceed0.

* fix Syncer logout alert

core/modules/syncer.js

@@ -472,7 +472,7 @@ Syncer.prototype.handleLogoutEvent = function() {
 	if(this.syncadaptor.logout) {
 		this.syncadaptor.logout(function(err) {
 			if(err) {
-				self.logger.alert(err);
+				self.displayError("Logout Error",err);
 			} else {
 				self.getStatus();
 			}