libpq's exports.txt was overlooked in commit 36d10876, which the
buildfarm is quite unhappy about.

Also, I'd gathered that the plan included renaming PQgetSSLKeyPassHook
to PQgetSSLKeyPassHook_OpenSSL, but that didn't happen in the patch
as committed.  I'm taking it on my own authority to do so now, since
the window before beta1 is closing fast.