reverseproxy: Fix support for "4xx" type status codes

modules/caddyhttp/reverseproxy/caddyfile.go

@@ -1012,6 +1012,7 @@ func (h *Handler) parseNamedResponseMatcher(d *caddyfile.Dispenser, matchers map
 				}
 
 				matcher.Headers = http.Header(headerMatcher)
+
 			case "status":
 				if matcher.StatusCode == nil {
 					matcher.StatusCode = []int{}
@@ -1023,12 +1024,16 @@ func (h *Handler) parseNamedResponseMatcher(d *caddyfile.Dispenser, matchers map
 				}
 
 				for _, arg := range args {
-					statusNum, err := strconv.Atoi(arg)
+					if len(arg) == 3 && strings.HasSuffix(arg, "xx") {
+						arg = arg[:1]
+					}
+					statusNum, err := strconv.Atoi(arg[:1])
 					if err != nil {
 						return d.Errf("bad status value '%s': %v", arg, err)
 					}
 					matcher.StatusCode = append(matcher.StatusCode, statusNum)
 				}
+
 			default:
 				return d.Errf("unrecognized response matcher %s", d.Val())
 			}