Update platform/linux/do_debian_package.sh

Co-authored-by: Benoit Pierre <benoit.pierre@gmail.com>

platform/linux/do_debian_package.sh

@@ -83,7 +83,7 @@ if command_exists "${COMMAND}"; then
     } > "${BASE_DIR}/DEBIAN/control"
 
     # use absolute path to luajit in reader.lua
-    sed -i 's/.\/luajit/\/usr\/lib\/koreader\/luajit/' "${BASE_DIR}/usr/lib/koreader/reader.lua"
+    sed -i 's,./luajit,/usr/lib/koreader/luajit,' "${BASE_DIR}/usr/lib/koreader/reader.lua"
 
     # use debian packaged fonts instead of our embedded ones to save a couple of MB.
     # Note: avoid linking against fonts-noto-cjk-extra, cause it weights ~200MB.