TranslateWord2: Don't process invalid phonemes.

If ph_code is not located in the phoneme_tab, the resulting ph
value will be NULL. This does not normally happen, but it can
happen if word_phonemes contains garbage data, such as with the
1.49.2 multi-word logic when processing words like 'riposted'.

src/libespeak-ng/translate.c

 
 		// Add the phonemes to the first stage phoneme list (ph_list2)
 		ph = phoneme_tab[ph_code];
+		if (ph == NULL) {
+			printf("Invalid phoneme code %d\n", ph_code);
+			continue;
+		}
 
 		if (ph_code == phonSWITCH) {
 			ph_list2[n_ph_list2].phcode = ph_code;