SuperBuild: cleanup for geotiff

SuperBuild/CMake/External_geotiff.cmake

@@ -28,11 +28,6 @@ else()
     ADD_SUPERBUILD_CMAKE_VAR(ZLIB_LIBRARY)
     ADD_SUPERBUILD_CMAKE_VAR(JPEG_INCLUDE_DIR)
     ADD_SUPERBUILD_CMAKE_VAR(JPEG_LIBRARY)
-  else()
-    ADD_SUPERBUILD_CONFIGURE_VAR(TIFF_ROOT --with-libtiff)
-    ADD_SUPERBUILD_CONFIGURE_VAR(PROJ_ROOT --with-proj)
-    ADD_SUPERBUILD_CONFIGURE_VAR(ZLIB_ROOT --with-zlib)
-    ADD_SUPERBUILD_CONFIGURE_VAR(JPEG_ROOT --with-jpeg)
   endif()
 
   ExternalProject_Add(${proj}