stris(1): use String::default instead of String::new

src/stris.rs

@@ -43,7 +43,7 @@ fn main() -> ExitCode {
 	let mut optind = 1;
 	let mut reqs = Reqs {
 		ascii: false, blank: false, cntrl: false, digit: false, lower: false,
-		upper: false, inuse: false, extra: String::new()
+		upper: false, inuse: false, extra: String::default()
 	};
 
 	while let Some(opt) = argv.getopt("7bcdi:lu") {