opensmtpd: fix everything.

- Ensure BDB backend is found.
- Don't find OpenBSD stdlib functions defined in libressl without prototypes.
  This resulted in reallocarray() returning truncated addresses in sendmail(1).

srcpkgs/opensmtpd/template

@@ -1,11 +1,15 @@
 # Template file for 'opensmtpd'
 pkgname=opensmtpd
 version=5.9.2p1
-revision=3
+revision=4
 build_style=gnu-configure
 configure_args="--sysconfdir=/etc/smtpd --sbindir=/usr/bin
- --with-path-socket=/run --with-mantype=doc --with-pie --enable-table-db
+ --with-path-socket=/run --with-mantype=doc --with-pie --with-table-db
- --with-path-CAfile=/etc/ssl/certs/ca-certificates.crt"
+ --with-path-CAfile=/etc/ssl/certs/ca-certificates.crt
+ ac_cv_func_explicit_bzero=no
+ ac_cv_func_reallocarray=no
+ ac_cv_func_strlcat=no
+ ac_cv_func_strlcpy=no"
 hostmakedepends="automake libtool pkg-config bison"
 makedepends="zlib-devel libressl-devel libevent-devel db-devel libasr-devel"
 depends="ca-certificates"