remove unused declarations of ChangePhonemes_ru() and struct CHANGEPH

these are the only references in the code.

src/libespeak-ng/translate.h

@@ -589,16 +589,6 @@ typedef struct {
 	int suffix_add_e;      // replace a suffix (which has the SUFX_E flag) with this character
 } LANGUAGE_OPTIONS;
 
-// a parameter of ChangePhonemes()
-typedef struct {
-	int flags;
-	unsigned char stress;          // stress level of this vowel
-	unsigned char stress_highest;  // the highest stress level of a vowel in this word
-	unsigned char n_vowels;        // number of vowels in the word
-	unsigned char vowel_this;      // syllable number of this vowel (counting from 1)
-	unsigned char vowel_stressed;  // syllable number of the highest stressed vowel
-} CHANGEPH;
-
 typedef struct {
 	LANGUAGE_OPTIONS langopts;
 	int translator_name;
@@ -769,7 +759,6 @@ void print_dictionary_flags(unsigned int *flags, char *buf, int buf_len);
 char *DecodeRule(const char *group_chars, int group_length, char *rule, int control);
 
 void MakePhonemeList(Translator *tr, int post_pause, bool new_sentence);
-int ChangePhonemes_ru(Translator *tr, PHONEME_LIST2 *phlist, int n_ph, int index, PHONEME_TAB *ph, CHANGEPH *ch);
 void ApplySpecialAttribute2(Translator *tr, char *phonemes, int dict_flags);
 void AppendPhonemes(Translator *tr, char *string, int size, const char *ph);