Syntax error or access violation Fix for Dashboard

https://github.com/getcandy/getcandy/issues/9

src/Http/Livewire/Dashboard.php

@@ -83,7 +83,7 @@ public function getReturningCustomersPercentProperty()
                 'address_join.contact_email',
                 '=',
                 "{$table}.contact_email"
-            )->groupBy("{$table}.id");
+            )->groupBy("{$table}.id","{$table}.contact_email");
 
         $total = $query->clone()->get()->count();