remove useless methods (base class has identical implementations)

src/plugins/debugger/gdb/termgdbadapter.cpp

@@ -141,10 +141,6 @@ void TermGdbAdapter::interruptInferior()
         debugMessage(_("CANNOT INTERRUPT %1").arg(attachedPID));
 }
 
-void TermGdbAdapter::shutdown()
-{
-}
-
 void TermGdbAdapter::stubError(const QString &msg)
 {
     showMessageBox(QMessageBox::Critical, tr("Debugger Error"), msg);

src/plugins/debugger/gdb/termgdbadapter.h

@@ -61,8 +61,6 @@ public:
     void startInferior();
     void startInferiorPhase2();
     void interruptInferior();
-    void shutdown();
-    const char *inferiorShutdownCommand() const { return "kill"; }
 
 private:
     void handleStubAttached(const GdbResponse &response);