ENH: env variable to silent non critical OTB outputs.

docker/dockerfile

@@ -100,6 +100,7 @@ ENV LD_LIBRARY_PATH="/opt/otb/lib:$LD_LIBRARY_PATH"
 ENV OTB_APPLICATION_PATH="/opt/otb/lib/otb/applications"
 ENV PROJ_LIB="$DEPS_INSTALL_PREFIX/share/proj"
 ENV GDAL_DATA="$DEPS_INSTALL_PREFIX/share/gdal"
+ENV OTB_LOGGER_LEVEL="CRITICAL"
 
 RUN useradd -s /bin/bash -m ubuntu
 USER ubuntu