CMake: Fix the comment about versions. [skip ci]

[tcpdump] / tests / vtp_asan-2.out

    1  2023-11-18 11:13:40.2148532227 FRF.16 Frag, seq 193, Flags [Begin, End], UI 08! VTPv69, Message Subset advertisement (0x02), length 262131
        Domain name: , Seq number: 0, Config Rev fb499603 (invalid) [|vtp]