Fix RemoteLinux debugging.

Make double sure we use "target extended-remote".

Change-Id: I4e96d1d6a9dc5393318409503adb835afb229fd2
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/remotelinux/remotelinuxdebugsupport.cpp

@@ -102,6 +102,7 @@ DebuggerStartParameters LinuxDeviceDebugSupport::startParameters(const AbstractR
     }
     if (aspect->useCppDebugger()) {
         params.multiProcess = true;
+        aspect->setUseMultiProcess(true); // TODO: One should suffice.
         params.languages |= CppLanguage;
         QStringList args = runConfig->arguments();
         if (aspect->useQmlDebugger())