Bug 21662: (follow-up) Drop YAML::XS, use YAML

I mistakenly left us using YAML::XS when we don't already depend upon
it. YAML is a sufficent alternative that we do already require.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

about.pl

@@ -32,7 +32,7 @@ use XML::Simple;
 use Config;
 use Search::Elasticsearch;
 use Try::Tiny;
-use YAML::XS qw/LoadFile/;
+use YAML qw/LoadFile/;
 
 use C4::Output;
 use C4::Auth;