Unset PREFERRED_PROVIDER_jpeg* in sample conf file
Unset PREFERRED_PROVIDER_jpeg* in sample conf file

The local.conf.sample provided by meta-gumstix doesn't need to set a
preferred provider for jpeg as no other jpeg providers are pulled in
by the default set of layers.  Libjpeg-turbo is pulled in by meta-oe.

Signed-off-by: Ash Charles <80cee6ff557ba1c5981cd5d98755c09f634abbac@gmail.com>

scottellis/meta-gumstix,scottellis/meta-gumstix,gumstix/meta-gumstix,gumstix/meta-gumstix,gumstix/meta-gumstix