Allow default to be used.

cmd/boulder-wfe2/main.go

@@ -160,11 +160,11 @@ type Config struct {
 		}
 
 		// MaxNames is the maximum number of subjectAltNames in a single cert.
-		// The value supplied MUST be greater than 0 and no more than 100,
+		// The value supplied SHOULD be greater than 0 and no more than 100,
 		// defaults to 100. These limits are per section 7.1 of our combined
 		// CP/CPS, under "DV-SSL Subscriber Certificate". The value must match
 		// the CA and RA configurations.
-		MaxNames int `validate:"required,min=1,max=100"`
+		MaxNames int `validate:"min=0,max=100"`
 	}
 
 	Syslog        cmd.SyslogConfig