Don't convert header values to lowercase

jni/AndroidWebRequest.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 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 234 matching lines @@
       if (!jHeaderValue)
         break;
 
       std::string headerName = GetString(jniEnv, jHeaderName);
       std::string headerValue = GetString(jniEnv, jHeaderValue);
 
       headerName = TrimString(headerName);
       headerValue = TrimString(headerValue);
 
       std::transform(headerName.begin(), headerName.end(), headerName.begin(), ::tolower);
-      std::transform(headerValue.begin(), headerValue.end(), headerValue.begin(), ::tolower);
 
       result.responseHeaders.push_back(std::pair<std::string, std::string>(headerName, headerValue));
 
       i++;
     }
     D(D_WARN, "Finished downloading");
 
     result.status = AdblockPlus::DefaultWebRequest::NS_OK;
   }
   catch(JavaException& e)
@@ skipping 17 matching lines @@
   {
     D(D_ERROR, "Unknown exception");
     result.status = AdblockPlus::DefaultWebRequest::NS_ERROR_FAILURE;
   }
 
   if (stat == JNI_EDETACHED)
     globalJvm->DetachCurrentThread();
 
   return result;
 }