Initialize intercept_allow_setid to true if we use ptrace(2) and seccomp(2).

src/sudo_exec.h

@@ -146,7 +146,6 @@ char **sudo_preload_dso(char *envp[], const char *dso_file, int intercept_fd);
 
 /* exec_ptrace.c */
 bool exec_ptrace_handled(pid_t pid, int status, void *intercept);
-bool have_seccomp_action(const char *action);
 bool set_exec_filter(void);
 int exec_ptrace_seize(pid_t child);