LuaHTTP: Use binary instead of ASCII when serving rawfile

Close #5949
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
(cherry picked from commit 97111d1d)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

share/lua/intf/http.lua

@@ -211,7 +211,7 @@ function rawfile(h,path,url,acl_)
             else
                 vlc.msg.dbg("Reloading `"..filename.."'")
             end
-            page = io.open(filename):read("*a")
+            page = io.open(filename,"rb"):read("*a")
             mtime = new_mtime
         end
         return page