nixos/wrappers: require argc to be at least one

setuid applications were exploited in the past with an empty
argv, such as pkexec using CVE-2021-4034.

Changed files
+1
nixos
modules
security
wrappers
+1
nixos/modules/security/wrappers/wrapper.c
···
}
int main(int argc, char **argv) {
+
ASSERT(argc >= 1);
char *self_path = NULL;
int self_path_size = readlink_malloc("/proc/self/exe", &self_path);
if (self_path_size < 0) {