remove comment

(used at line 1236)

(cherry picked from commit a6e8ba19)

node/src/chain_spec/gen_genesis_data.rs

@@ -188,7 +188,7 @@ struct IdentityV1 {
     /// whether the identity is revoked (manually or automatically)
     revoked: bool,
     /// timestamp at which the next cert can be emitted
-    next_cert_issuable_on: TimestampV1, // TODO: unused?
+    next_cert_issuable_on: TimestampV1,
     /// balance of the account of this identity
     balance: u64,
     /// certs received with their expiration timestamp