Bug 24756: [19.11.X] Catch two failed to load-variations in Security.t

Bug 24756: [19.11.X] Catch two failed to load-variations in Security.t

Test 7 in Security.t failed when 'failed to load HTTP resource' was
returned by libxml2 instead of 'failed to load external entity'.

We now remove the debugging with Dumper again and adjust the regex to
include both variations.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Joy Nelson <joy@bywatersolutions.com>
(cherry picked from commit 09b8c38a8264c55ae5e7187cb76e608a072729fd)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>