Demote GTOPO30 plugin to unsupported

Description

Mailing list discussion:
https://sourceforge.net/p/geotools/mailman/message/36349984/

The goal is to completely retire this plugin in short term.

Environment

None

Status

Assignee

Nuno Oliveira

Reporter

Nuno Oliveira

Triage

None

Components

Fix versions

Priority

Medium
Configure