Util/Pod.pm: Fix uninitialized $podinfo{lastsecttext} on empty input
Util/Pod.pm: Fix uninitialized $podinfo{lastsecttext} on empty input

Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13898)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl