BUG: 1296 run subsamplefilter also with single thread in inverse mode

Modules/Filtering/Wavelet/include/otbWaveletFilterBank.txx

@@ -1178,6 +1178,7 @@ WaveletFilterBank<TInputImage, TOutputImage, TWaveletOperator, Wavelet::INVERSE>
       typename FilterType::Pointer overSampledLowPass = FilterType::New();
       overSampledLowPass->SetInput(cropedLowPass);
       overSampledLowPass->SetSubsampleFactor(delta);
+	  overSampledLowPass->SetNumberOfThreads(1);
       overSampledLowPass->Update();
 
       InputImagePointerType cropedHighPass = InputImageType::New();
@@ -1196,6 +1197,7 @@ WaveletFilterBank<TInputImage, TOutputImage, TWaveletOperator, Wavelet::INVERSE>
       typename FilterType::Pointer overSampledHighPass = FilterType::New();
       overSampledHighPass->SetInput(cropedHighPass);
       overSampledHighPass->SetSubsampleFactor(delta);
+	  overSampledHighPass->SetNumberOfThreads(1);
       overSampledHighPass->Update();
 
       InnerProductType innerProduct;