Task #9048: Use "v" in tag name for casarest as well

Docker/lofar-base/Dockerfile.tmpl

@@ -121,7 +121,7 @@ RUN sudo apt-get install -y wget git cmake g++ gfortran flex bison libblas-dev l
 RUN sudo apt-get install -y git cmake g++ gfortran libboost-system-dev libboost-thread-dev libhdf5-dev && \
     mkdir -p ${INSTALLDIR}/casarest/build && \
     cd ${INSTALLDIR}/casarest && git clone https://github.com/casacore/casarest.git src && \
-    if [ "${CASAREST_VERSION}" != "latest" ]; then cd ${INSTALLDIR}/casarest/src && git checkout tags/${CASAREST_VERSION}; fi && \
+    if [ "${CASAREST_VERSION}" != "latest" ]; then cd ${INSTALLDIR}/casarest/src && git checkout tags/v${CASAREST_VERSION}; fi && \
     cd ${INSTALLDIR}/casarest/build && cmake -DCMAKE_INSTALL_PREFIX=${INSTALLDIR}/casarest -DCASACORE_ROOT_DIR=${INSTALLDIR}/casacore -DWCSLIB_ROOT_DIR=${INSTALLDIR}/wcslib -DCFITSIO_ROOT_DIR=${INSTALLDIR}/cfitsio ../src/ && \
     cd ${INSTALLDIR}/casarest/build && make -j ${J} && \
     cd ${INSTALLDIR}/casarest/build && make install && \