remove dangerous function

Svelto.ECS/EGID.cs

@@ -35,10 +35,5 @@ namespace Svelto.ECS
         {
             return (long)groupId << 32 | ((long)(uint)entityId & 0xFFFFFFFF);
         }
-        
-        public static implicit operator int(EGID id) 
-        {
-            return id.entityID;
-        }
     }
 }