i_CHANGE_PHONEME2 is not used and the code conflicts with i_ADD_LENGTH, so remove it

src/libespeak-ng/synthdata.c

@@ -879,8 +879,6 @@ void InterpretPhoneme(Translator *tr, int control, PHONEME_LIST *plist, PHONEME_
 				}
 				phdata->ipa_string[ix] = 0;
 			} else if (instn2 < N_PHONEME_DATA_PARAM) {
-				if (instn2 == i_CHANGE_PHONEME2)
-					phdata->pd_param[i_CHANGE_PHONEME] = data; // also set ChangePhoneme
 				phdata->pd_param[instn2] = data;
 				if ((instn2 == i_CHANGE_PHONEME) && (control & 0x100)) {
 					// found ChangePhoneme() in PhonemeList mode, exit

src/libespeak-ng/synthesize.h

@@ -284,13 +284,11 @@ typedef struct {
 #define i_LENGTH_MOD     0x09
 #define i_SET_LENGTH     0x0a
 #define i_LONG_LENGTH    0x0b
-#define i_CHANGE_PHONEME2 0x0c  // not yet used
+#define i_ADD_LENGTH     0x0c
 #define i_IPA_NAME       0x0d
 
 #define i_CHANGE_IF      0x10  // 0x10 to 0x14
 
-#define i_ADD_LENGTH     0x0c
-
 // conditions and jumps
 #define i_CONDITION  0x2000
 #define i_OR         0x1000  // added to i_CONDITION