MKCRYPTO=no causes build failure in libdns

[Paul Goyette <paul%whooppee.com@localhost>]

While building a system with MKCRYPTO=no (to re-verify PR 23663!) I ran 
into the following error:

--- ds.d ---
In file included from /build/netbsd-local/src/external/bsd/bind/dist/lib/dns/ds.c:44:0:
/build/netbsd-local/src/external/bsd/bind/dist/lib/dns/dst_gost.h:29:25: fatal error: openssl/evp.h: No such file or directory

If libdns requires openssl, should we even try to build when MKCRYPTO is 
set to no?


+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
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