Issue 4832 - remove API allowing changing of FileSystem after Initialization of JsEngine

src/JsEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 313 matching lines @@
   for (int i = 0; i < arguments.Length(); i++)
     list.push_back(JsValue(shared_from_this(), arguments[i]));
   return list;
 }
 
 AdblockPlus::FileSystemPtr AdblockPlus::JsEngine::GetAsyncFileSystem() const
 {
   return fileSystem;
 }
 
-void AdblockPlus::JsEngine::SetFileSystem(const AdblockPlus::FileSystemSyncPtr& val)
-{
-  if (!val)
-    throw std::runtime_error("FileSystem cannot be null");
-
-  fileSystem.reset(new DefaultFileSystem(val));
-}
-
 AdblockPlus::LogSystem& AdblockPlus::JsEngine::GetLogSystem()
 {
   return *logSystem;
 }
 
 void AdblockPlus::JsEngine::SetGlobalProperty(const std::string& name,
                                               const AdblockPlus::JsValue& value)
 {
   auto global = GetGlobalObject();
   global.SetProperty(name, value);
 }