Update FUNDING.yml

.github/FUNDING.yml

@@ -1,5 +1,5 @@
 # These are supported funding model platforms
 
 # github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
-liberapay: borgbackup
-#custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']
+# liberapay: borgbackup
+custom: ['https://www.borgbackup.org/support/fund.html']