Comment 9 for bug 497319

Seems like there is no point bothering with adding Rwandatel, which appears to
have lost its mobile operation license in April 2011. I've sent a patch upstream to add Tigo.

You *could* take this patch from the upstream bug tracker this way:
sudo patch -p1 /usr/share/mobile-broadband-provider-info/serviceproviders.xml < tigo.diff

... but there isn't such a huge point in doing this since it's easy enough to add the APN when creating a connection :)