Add Requires: libxslt if BUILD_XMLCONF is defined

Signed-off-by: Steven Dake <sdake@redhat.com>
Reviewed-by: Angus Salkled <asalkeld@redhat.com>

corosync.spec.in

@@ -54,6 +54,9 @@ BuildRequires: dbus-devel
 %if %{with systemd}
 BuildRequires: systemd-units
 %endif
+%if %{with xmlconf}
+Requires: libxslt
+%endif
 
 BuildRoot: %(mktemp -ud %{_tmppath}/%{name}-%{version}-%{release}-XXXXXX)