exim build failure.

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

Getting exim build failures ever since the last version update due to:

/bin/sh ../scripts/Configure-os.h
gcc -DMACRO_PREDEF macro_predef.c
gcc -c -O2 -I/usr/include -I/usr/pkg/include -fPIC -D_FORTIFY_SOURCE=2 
-DMACRO_PREDEF -I/usr/ -I/usr/pkg/include -o macro_predef.o macro_predef.c
In file included from exim.h:535:0,
                 from macro_predef.c:12:
hintsdb.h:465:4: error: #error Berkeley DB version 1 is no longer supported
 #  error Berkeley DB version 1 is no longer supported
    ^~~~~
hintsdb.h:755:15: error: unknown type name 'EXIM_DB'
 static inline EXIM_DB *
               ^~~~~~~

So it looks like exim no longer supports the built in libdb. I can see 
that there is pkgsrc logic for pulling in newer versions but I'm not 
sure how to make the exim package do that.

Mike