Merge branch 'fix_libsvm_verbosity' into 'develop'

BUG: fix verbosity of libsvm

See merge request orfeotoolbox/otb!308

Modules/Learning/Supervised/include/otbLibSVMMachineLearningModel.hxx

@@ -66,7 +66,7 @@ LibSVMMachineLearningModel<TInputValue,TOutputValue>
   this->m_Problem.l = 0;
   this->m_Problem.y = nullptr;
   this->m_Problem.x = nullptr;
-#ifndef NDEBUG
+#ifdef NDEBUG
   svm_set_print_string_function(&otb::Utils::PrintNothing);
 #endif
 }