[PATCH] setopt: Fix disabling all protocols

[PATCH] setopt: Fix disabling all protocols

When disabling all protocols without enabling any, the resulting
set of allowed protocols remained the default set.  Clearing the
allowed set before inspecting the passed value from --proto make
the set empty even in the errorpath of no protocols enabled.

Co-authored-by: Dan Fandrich <dan@telarity.com>
Reported-by: Dan Fandrich <dan@telarity.com>
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
Closes: #13004
Backported by: Guilherme Puida Moreira <guilherme@puida.xyz>
 * Small change in the Makefile to add a new test.

Gbp-Pq: Name CVE-2024-2004.patch