Fix accidental replace of assert!(result.unwrap() with expect_err instead of expect

Signed-off-by: Jacinta Ferrant <jacinta@trustmachines.co>

Author: jferrant

stacks-signer/src/tests/chainstate.rs

@@ -288,7 +288,7 @@ fn check_proposal_reorg_timing_bad() {
 #[test]
 fn check_proposal_reorg_timing_ok() {
     let result = reorg_timing_testing("reorg_timing_okay", 30, 30);
-    result.expect_err("Proposal should validate okay, because the reorg occurred in a block whose proposed time was close to the sortition");
+    result.expect("Proposal should validate okay, because the reorg occurred in a block whose proposed time was close to the sortition");
 }
 
 #[test]