Noissue - fix Uint32SetEntry::erase what could lead to a data loss

compiled/IntMap.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 45 matching lines @@
       return first == KEY_INVALID;
     }
 
     bool is_deleted() const
     {
       return first == KEY_DELETED;
     }
 
     void erase()
     {
-      first = KEY_INVALID;
+      first = KEY_DELETED;
     }
 
     static size_type hash(key_type_cref key)
     {
       return key;
     }
   };
 
   template<typename Value>
   struct Uint32MapEntry : Uint32SetEntry
@@ skipping 15 matching lines @@
     }
   };
 }
 
 using Uint32Set = Set<Uint32Map_internal::Uint32SetEntry>;
 
 template<typename Value>
 using Uint32Map = Map<Uint32Map_internal::Uint32MapEntry<Value>>;
 
 ABP_NS_END