INSTALL: Update to links
Kristjan ESPERANTO has provided PR to update links in INSTALL: https://github.com/freeciv/freeciv/pull/35
For master/S3_1, I've only added update to "last changed" date. For S3_0 had also adjust to the fact that there's no sqlite dependency (and thus no link) in there.
Kristjan ESPERANTO has provided PR to update links in INSTALL: https://github.com/freeciv/freeciv/pull/35