Issue 3501 - use hardcoded value until there is a real error message

src/plugin/PluginClass.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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 1606 matching lines @@
         std::wstring upToDateText = dictionary->Lookup("updater", "update-already-up-to-date-text");
         std::wstring upToDateTitle = dictionary->Lookup("updater", "update-already-up-to-date-title");
         pClass->notificationMessage.SetTextAndIcon(upToDateText, upToDateTitle, TTI_INFO);
         break;
       }
     case WM_UPDATE_CHECK_ERROR:
       {
         Dictionary* dictionary = Dictionary::GetInstance();
         std::wstring errorText = dictionary->Lookup("updater", "update-error-text");
         std::wstring errorTitle = dictionary->Lookup("updater", "update-error-title");
+        // use hardcoded value until there is a real error message
+        ReplaceString(errorText , L"?1?", L"Unknown error");

[Eric, 2016/01/13 15:14:13]

I'm uncomfortable with putting an English phrase into a translated UI element.
The empty string would be better, which we could do with L"\"\"" as the
substitution string.

I'd actually prefer to change the text in "update-error-text" to remove the
substitution entirely, but that means more translation work. Using the empty
string would be acceptable.

Are the error text strings to be presented to the user already present as
translated strings?

         pClass->notificationMessage.SetTextAndIcon(errorText, errorTitle, TTI_ERROR);
         break;
       }
     case WM_DOWNLOADING_UPDATE:
       {
         Dictionary* dictionary = Dictionary::GetInstance();
         std::wstring downloadingText = dictionary->Lookup("updater", "downloading-update-text");
         std::wstring downloadingTitle = dictionary->Lookup("updater", "downloading-update-title");
         pClass->notificationMessage.SetTextAndIcon(downloadingText, downloadingTitle, TTI_INFO);
         break;
@@ skipping 67 matching lines @@
   s_criticalSectionLocal.Unlock();
 
   return icon;
 }
 
 ATOM CPluginClass::GetAtomPaneClass()
 {
   return s_atomPaneClass;
 }