Encode.pm change to the UTF8 flag

Encode.pm change to the UTF8 flag

In the past, decode_utf8() silently ignored attempts to decode data
with the UTF8 flag on. However, Encode.pm changed around 2.53 and
resulted in wide-character errors preventing the likes of
--load-all-sample from working.

Since our data should already be UTF8 when it hits these functions, we
should not be trying to decode it in the first place.

Signed-off-by: Dan Wells <dbw2@calvin.edu>