Workaround for failure to build when Bazaar has not been configured with a username

[Depends on #19 & #20]

Interim workaround/fix for #5 / <https://bugs.launchpad.net/kicad/+bug/1248627> to not let an instance of Bazaar which has not been configured with a username break things. Ideally this fix should be applied upstream at KiCad (a patch has been submitted) but applying this enables the formula to work in the interim.