ErrorCode: update PAYMENT_PLUGIN_TIMEOUT message template
ErrorCode: update PAYMENT_PLUGIN_TIMEOUT message template

See https://github.com/killbill/killbill/issues/390.

Signed-off-by: Pierre-Alexandre Meyer <ff019a5748a52b5641624af88a54a2f0e46a9fb5@mouraf.org>

maguero/killbill-api,maguero/killbill-api,killbill/killbill-api,killbill/killbill-api