VCS[Mercurial]: Remove LANG=C setting

as it breaks the log output.
Task-number: QTCREATORBUG-1623

src/plugins/mercurial/mercurialclient.cpp

@@ -121,8 +121,6 @@ bool MercurialClient::executeHgSynchronously(const QString  &workingDir,
     QProcess hgProcess;
     if (!workingDir.isEmpty())
         hgProcess.setWorkingDirectory(workingDir);
-    MercurialJobRunner::setProcessEnvironment(hgProcess);
-
     const MercurialSettings &settings = MercurialPlugin::instance()->settings();
     const QString binary = settings.binary();
     const QStringList arguments = settings.standardArguments() + args;