Fix consensus test single_server_propose_1

[fakedev9999]

single_server_propose_1 keeps failing in CI with the following logs.

failures:

---- single_server_propose_1 stdout ----
Checking node #0
The application panicked (crashed).
Message:  assertion failed: `(left == right)`
  left: `[]`,
 right: `[NonNilPreVoted(0, Hash256 { hash: bc864b9ae651999314869ff986870450925558d9f8bf0bb31d18f879fcb3e53b }, 1673586621624)]`
Location: consensus/tests/integration_test.rs:190

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.


failures:
    single_server_propose_1

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.35s

error: test failed, to rerun pass `-p simperby-consensus --test integration_test`
Error: The process '/home/runner/.cargo/bin/cargo' failed with exit code 101