QtcProcess: pass arguments only once to child process

When not using the ctrlc stub, then the whole arguments string was
passed to QProcess::start as one argument, prefixed to the actual
arguments.

Task-number: QTCREATORBUG-11514

Change-Id: I8111749b5c2f0a0abbfa3e9f8441bb5cdcfe0531
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

src/libs/utils/qtcprocess.cpp

@@ -706,6 +706,8 @@ void QtcProcess::start()
         if (m_useCtrlCStub) {
             args = QDir::toNativeSeparators(command);
             command = QCoreApplication::applicationDirPath() + QLatin1String("/qtcreator_ctrlc_stub.exe");
+        } else {
+            args.clear();
         }
         QProcess::start(command, QStringList(args));
     } else {