Initialize some locals in socks5 parsing code.

These confused GCC LTO, which thought they might be used
uninitialized.  I'm pretty sure that as long as 'res' indicates
success, they will always be set to something, but let's unconfuse
the compiler in any case.

src/core/proto/proto_socks.c

@@ -744,7 +744,7 @@ handle_socks_message(const uint8_t *raw_data, size_t datalen,
       res = SOCKS_RESULT_MORE_EXPECTED;
       goto end;
     } else if (req->socks_version != SOCKS_VER_5) {
-      int have_user_pass, have_no_auth;
+      int have_user_pass=0, have_no_auth=0;
       res = parse_socks5_methods_request(raw_data, req, datalen,
                                          &have_user_pass,
                                          &have_no_auth,