Update wicketd/src/rss_config.rs

help rustfmt with long strings :D

Co-authored-by: John Gallagher <john@oxidecomputer.com>

Author: internet-diglett

wicketd/src/rss_config.rs

@@ -716,7 +716,8 @@ pub fn validate_rack_subnet(
 
     // Do not allow addresses more specific than /56
     if rack_subnet_address.octets()[7..].iter().any(|x| *x != 0x00) {
-        return Err("rack subnet address is /56, but a more specific prefix was provided".into());
+        return Err("rack subnet address is /56, \
+                   but a more specific prefix was provided".into());
     };
 
     Ipv6Net::new(rack_subnet_address, 56).map_err(|e| e.to_string())