SampleApp: fixed warning about unbinding render targets when capturing back buffer
SampleApp: fixed warning about unbinding render targets when capturing back buffer

DiligentGraphics/DiligentSamples,DiligentGraphics/DiligentSamples,DiligentGraphics/DiligentSamples,DiligentGraphics/DiligentSamples,DiligentGraphics/DiligentSamples,DiligentGraphics/DiligentSamples