website: remove unused reference

debugging page was removed in:
https://vanadium-review.googlesource.com/#/c/23020/

Change-Id: I1e5a046f58c30c78b0c7d94c2e56540a007d1e58
diff --git a/content/syncbase/my-cloud-syncbase.md b/content/syncbase/my-cloud-syncbase.md
index bee12ea..38ffbfd 100644
--- a/content/syncbase/my-cloud-syncbase.md
+++ b/content/syncbase/my-cloud-syncbase.md
@@ -58,6 +58,3 @@
 The `DASHBOARD` button opens a page showing load and resource utilization for
 the instance.  The `DEBUG` button opens a page showing details about the
 instance like its blessings, stats, and a browse view of the databases.
-
-[Debugging]: /syncbase/guides/debugging.html
-