By Seamus Duff A rabies scare has rocked the set of Netflix’s upcoming adventurer reality show Bear Hunt – with celebrity contestants warned about potentially lethal bat bites. The new reality show will star 49-year-old explorer Bear Grylls who will be joined by a string of celebs in a jungle in Costa Rica – while Holly Willoughby, 43, will make her TV return as host of the show. The series is said to have attracted star signings including 48-year-old Spice Girl Mel B and 36-year-old rugby star Danny Cipriani \- among other rumoured big names. The stars taking part in the new show – which seem…