MLEHMANN ignores Perl newer than 5.22, disable feature signatures

Index: XS.pm
--- XS.pm.orig
+++ XS.pm
@@ -87,6 +87,7 @@ stuff). Or you can combine those features in whatever 
 
 package JSON::XS;
 
+no feature 'signatures';
 use common::sense;
 
 our $VERSION = '4.04';
