add refmiscinfo source and manual fields as they are needed for the nroff generation to prevent the xsl stylesheets from adding ugly FIXME entries

docs/refguide.xml

@@ -4,6 +4,8 @@
   <refmeta>
     <refentrytitle>nmap</refentrytitle>
     <manvolnum>1</manvolnum>
+    <refmiscinfo class="source">Nmap</refmiscinfo>
+    <refmiscinfo class="manual">Nmap Reference Guide</refmiscinfo>
   </refmeta>
   <refnamediv id='man-name'>
     <refname>nmap</refname>