Bug 24327: Add warning to the about page is AnonSugggestions but AnonymousPatron

Bug 24327: Add warning to the about page is AnonSugggestions but AnonymousPatron

This patch adds a warning to the about page if AnonSuggestions is set
but AnonymousPatron.

Test plan:
Turn on AnonSuggestions and set AnonymousPatron to 0
=> You see a warning on the about page
Turn on AnonSuggestions and set AnonymousPatron to an invalid value
=> You see a warning on the about page
Turn off AnonSuggestions
=> No warning
Turn on AnonSuggestions and set AnonymousPatron to a valid value
=> No warning

Signed-off-by: hc <hc@interleaf.ie>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>