fi: fix behaviour of S_2_TO_HEAVY (adding secondary stress)

Stress flag S_2_TO_HEAVY is currently only used by finnish.

Current behaviour skips adding secondary stress if the following syllable is heavy. The behaviour should be to skip adding secondary stress if the rest of the word (excluding last syllable) contains a heavy syllable.

Source of grammar rule and examples of expected behaviour: http://scripta.kotus.fi/visk/sisallys.php?p=13

src/libespeak-ng/dictionary.c

@@ -1373,6 +1373,19 @@ void SetWordStress(Translator *tr, char *output, unsigned int *dictionary_flags,
 				if ((stress == 3) && (stressflags & S_NO_AUTO_2))
 					continue; // don't use secondary stress
 
+                                // don't put secondary stress on a light syllable if the rest of the word (excluding last syllable) contains a heavy syllable
+				if ((v > 1) && (stressflags & S_2_TO_HEAVY) && (syllable_weight[v] == 0)) {
+					bool skip = false;
+					for (int i = v; i < vowel_count - 1; i++) {
+						if (syllable_weight[i] > 0) {
+							skip = true;
+							break;
+						}
+					}
+					if (skip == true)
+						continue;
+				}
+
 				if ((v > 1) && (stressflags & S_2_TO_HEAVY) && (syllable_weight[v] == 0) && (syllable_weight[v+1] > 0)) {
 					// don't put secondary stress on a light syllable which is followed by a heavy syllable
 					continue;