Fix the freedive mode detection.
Fix the freedive mode detection.

andysan/libdivecomputer,andysan/libdivecomputer,venkateshshukla/libdivecomputer,Poltsi/libdivecomputer-vms,glance-/libdivecomputer,venkateshshukla/libdivecomputer,josh-wambua/libdivecomputer,josh-wambua/libdivecomputer,henrik242/libdivecomputer,henrik242/libdivecomputer,glance-/libdivecomputer