ugly workaround to run under older perl

bin/account-manager.pl.in

@@ -5,7 +5,7 @@ use warnings;
 use utf8;
 use lib qw(@modulesdir@);
 use feature "switch";
-no warnings 'experimental::smartmatch';
+no if $] >= 5.017011, warnings => 'experimental::smartmatch';
 
 use Config::Tiny;
 use Data::Dumper;