fix(cli): avoid linebreak in empty input

#511

Author: escapedcat

@commitlint/cli/src/cli.js

@@ -121,7 +121,7 @@ async function main(options) {
 
 	const input = await (fromStdin ? stdin() : read(range, {cwd: flags.cwd}));
 
-	const messages = (Array.isArray(input) ? input : [input])
+	const messages = (Array.isArray(input) ? input : [input.trimEnd()])
 		.filter(message => typeof message === 'string')
 		.filter(Boolean);