Update domains.json (#2408)

Author: singlefinance

spaces/domains.json

@@ -892,6 +892,7 @@
   "vote.decubate.com": "decubategov.eth",
   "vote.nftprotect.app": "nftprotectapp.eth",
   "dao.gracie.network": "gracienetwork.eth",
+  "vote.singlefinance.io": "singlefinance.eth",
   "poll.daosquare.io": "poll.daosquare.eth",
   "vote.gravityfinance.io": "gravity-finance.eth",
   "governance.xdefi.io": "xdefigovernance.eth"