addPluralSuffixes: Also add heading \0 (#2106)

src/libespeak-ng/translateword.c

 // append plural suffixes depending on preceding letter
 static void addPluralSuffixes(int flags, Translator *tr, char last_char, char *word_phonemes)
 {
-	char word_zz[4] = { ' ', 'z', 'z', 0 };
-	char word_iz[4] = { ' ', 'i', 'z', 0 };
-	char word_ss[4] = { ' ', 's', 's', 0 };
+	char word_zz[5] = { 0, ' ', 'z', 'z', 0 };
+	char word_iz[5] = { 0, ' ', 'i', 'z', 0 };
+	char word_ss[5] = { 0, ' ', 's', 's', 0 };
 	if (flags & FLAG_HAS_PLURAL) {
 		// s or 's suffix, append [s], [z] or [Iz] depending on previous letter
 		if (last_char == 'f')
-			TranslateRules(tr, &word_ss[1], word_phonemes, N_WORD_PHONEMES,
+			TranslateRules(tr, &word_ss[2], word_phonemes, N_WORD_PHONEMES,
 			NULL, 0, NULL);
 		else if ((last_char == 0) || (strchr_w("hsx", last_char) == NULL))
-			TranslateRules(tr, &word_zz[1], word_phonemes, N_WORD_PHONEMES,
+			TranslateRules(tr, &word_zz[2], word_phonemes, N_WORD_PHONEMES,
 			NULL, 0, NULL);
 		else
-			TranslateRules(tr, &word_iz[1], word_phonemes, N_WORD_PHONEMES,
+			TranslateRules(tr, &word_iz[2], word_phonemes, N_WORD_PHONEMES,
 			NULL, 0, NULL);
 	}
 }