fix: race condition of x.signer in v1 consensus#445

wjrjerome merged 1 commit intodev-upgradeXinFinOrg/XDPoSChain:dev-upgradefrom

fix-race-condition-in-v1-x.signerXinFinOrg/XDPoSChain:fix-race-condition-in-v1-x.signerCopy head branch name to clipboard