gentoo: htpasswd: BCRYPT algorithm not supported on this platform

I'm making a note of it, as a google search didn't find the straightforward solution. In case you get the error "htpasswd: BCRYPT algorithm not supported on this platform" when using htpasswd -B on gentoo. The solution is to recompile apr-util with the openssl USE flag. Unfortunately it's switched off by default.

echo -e 'dev-libs/apr-util\topenssl\t# htpasswd: BCRYPT algorithm not supported on this platform' >> /etc/portage/package.use