[options] Rollback old behavior for configuratio files' encoding

Until agreed with some solution

youtube_dl/options.py

@@ -26,7 +26,11 @@ def _readOptions(filename_bytes, default=[]):
         except IOError:
             return default  # silently skip if file is not present
         try:
-            res = compat_shlex_split(optionf.read(), comments=True)
+            # FIXME: https://github.com/rg3/youtube-dl/commit/dfe5fa49aed02cf36ba9f743b11b0903554b5e56
+            contents = optionf.read()
+            if sys.version_info < (3,):
+                contents = contents.decode(preferredencoding())
+            res = compat_shlex_split(contents, comments=True)
         finally:
             optionf.close()
         return res