[tracker-miners] README.md: Remove obsolete mailing list link

[Sam Thursfield <sthursfield src gnome org>]

commit a4a1e9d1a95f73cfa87893b49f6f56d3b2c8b8cb
Author: Sam Thursfield <sam afuera me uk>
Date:   Fri May 14 20:33:00 2021 +0200

    README.md: Remove obsolete mailing list link

 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.md b/README.md
index bcd777545..82139efe0 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ Source code and issue tracking:
 
 All discussion related to Tracker happens on:
 
-  * <https://mail.gnome.org/mailman/listinfo/tracker-list>
+  * <https://discourse.gnome.org/tag/tracker>
 
 IRC channel #tracker on: