Fix safepath to match de-facto Linux standards

Linux distributions place `/usr/local` directories before their non-local counterparts in `$PATH`.

Unlike BSD, Linux distributions don't put packaged executables under `/usr/local`, instead it is used by the local user to place their own executables, potentially to replace system executables.

doas.c

@@ -238,8 +238,8 @@ mygetpwuid_r(uid_t uid, struct passwd *pwd, struct passwd **result)
 int
 main(int argc, char **argv)
 {
-	const char *safepath = "/bin:/sbin:/usr/bin:/usr/sbin:"
-	    "/usr/local/bin:/usr/local/sbin";
+	const char *safepath = "/usr/local/bin:/usr/local/sbin:"
+	    "/bin:/sbin:/usr/bin:/usr/sbin";
 	const char *confpath = NULL;
 	char *shargv[] = { NULL, NULL };
 	char *sh;