gprofng: fix bug 29351 - Move dynamic loading of modules to a later stage

gprofng/Changelog:
2022-07-22  Ruud van der Pas  <ruud.vanderpas@oracle.com>

	PR gprofng/29351
	* gp-display-html/gp-display-html.in: the dynamic loading of
	modules occurred too early, resulting in the generation of the
	man page to fail in case a module is missing; the loading part is
	now done somewhat later in the execution to avoid this problem.