Pass name of proxy effect to EffectSBSMS

Allows progress bar to show meaningful title when using SBSMS
time stretching in Change Pitch/Tempo.

src/effects/ChangePitch.cpp

@@ -185,6 +185,7 @@ bool EffectChangePitch::Process()
       double pitchRatio = 1.0 + m_dPercentChange / 100.0;
       SelectedRegion region(mT0, mT1);
       EffectSBSMS proxy;
+      proxy.mProxyEffectName = XO("High Quality Pitch Change");
       proxy.setParameters(1.0, pitchRatio);
 
       return proxy.DoEffect(mUIParent, mProjectRate, mTracks, mFactory, &region, false);