Update pr-mess_x-road_message_protocol.md
Update pr-mess_x-road_message_protocol.md

Corrected quotation in 2.1
vrk-kpa/X-Road,vrk-kpa/X-Road,ria-ee/X-Road,vrk-kpa/X-Road,vrk-kpa/X-Road,ria-ee/X-Road,vrk-kpa/X-Road,vrk-kpa/X-Road,ria-ee/X-Road,ria-ee/X-Road,vrk-kpa/X-Road,ria-ee/X-Road,vrk-kpa/X-Road,ria-ee/X-Road,ria-ee/X-Road,ria-ee/X-Road