Also update the toolchain to latest versions. This includes a security fix for
apache-xml-security-c.

Releaseinfo:    https://wiki.shibboleth.net/confluence/display/SP3/ReleaseNotes
Security:       5786185a-9a43-11e8-b34b-6cc21735f730
Security:       https://shibboleth.net/community/advisories/secadv_20180803.txt