Figure out whether builds for < SailfishOS 3.3 are possible
Low priority, but since we have to redo the contact-name lookup, we may as well try building for older Sailfishes. Currently, we require 3.3 for the contact name field, but after #231 (closed) and #132 (closed), this isn't really a blocker any more. Seems like we'll have to make a separate build, because of the older glibc.