SuperBuild: allow no download if fonts are already in download dir

SuperBuild/CMake/font_qt.cmake

@@ -25,10 +25,19 @@ if( NOT DOWNLOAD_LOCATION )
 endif()
 
 file(MAKE_DIRECTORY ${INSTALL_DIR}/lib/fonts/)
+
+if ( EXISTS "${DOWNLOAD_LOCATION}/dejavu-fonts-ttf-2.37.tar.bz2" )
+  file( MD5 "${DOWNLOAD_LOCATION}/dejavu-fonts-ttf-2.37.tar.bz2" MD5_FONT )
+endif()
+
+SET(CMAKE_TLS_VERIFY "OFF")
+if ( NOT ( "${MD5_FONT}" STREQUAL "d0efec10b9f110a32e9b8f796e21782c" ) )
+MESSAGE("DOWNLOADING FONTS")
 file(DOWNLOAD 
-  http://sourceforge.net/projects/dejavu/files/dejavu/2.37/dejavu-fonts-ttf-2.37.tar.bz2
+  https://netix.dl.sourceforge.net/project/dejavu/dejavu/2.37/dejavu-fonts-ttf-2.37.tar.bz2
   ${DOWNLOAD_LOCATION}/dejavu-fonts-ttf-2.37.tar.bz2
   EXPECTED_MD5 d0efec10b9f110a32e9b8f796e21782c)
+endif()
 
 execute_process(
 COMMAND ${CMAKE_COMMAND} -E tar -xf ${DOWNLOAD_LOCATION}/dejavu-fonts-ttf-2.37.tar.bz2