Incorrect revision link when candidate withdraws

[samliew]

See https://chat.stackexchange.com/messages/59451396/history

[Oaphi]

Reworked nominationLink getter to not rely on replace and just use the information made available by the Election class:

se-electionbot/src/election.js

Lines 123 to 130 in 554c689

	get nominationLink() {
	const { _nominationLink, hasWithdrawn, election } = this;
	const postId = matchNumber(/#post-(\d+)/, _nominationLink);
	// If withdrawn, change to post history as original post can longer be viewed
	return hasWithdrawn ? `${election.siteUrl}/posts/${postId}/revisions` : _nominationLink;
	}

Combined with the previous changes that add a nominee to the list only once (using Map indexed on userId), the issue is impossible to encounter now.