Remove broken link

Author: joto

_includes/sponsors.html

@@ -5,5 +5,4 @@
 <p>We thank our former sponsor <a href="https://www.mapbox.com/">Mapbox</a> for
 their support over many years as well as <a
 href="https://www.geofabrik.de/">Geofabrik</a>, <a
-href="https://www.cybertec-postgresql.com/">Cybertec</a>, and <a
-href="https://gis-ops.com/">GIS•OPS</a>.</p>
+href="https://www.cybertec-postgresql.com/">Cybertec</a>, and GIS•OPS.</p>