Don't replace rhotic with rzd. 'rhotic' is used on r-type consonants.

src/libespeak-ng/compiledata.c

 	{ "unstressed",   tPHONEME_FLAG, phUNSTRESSED },
 	{ "nolink",       tPHONEME_FLAG, phNOLINK },
 	{ "brkafter",     tPHONEME_FLAG, phBRKAFTER },
-	{ "rhotic",       tPHONEME_FLAG, phRHOTIC }, // TODO (deprecated): use 'rzd' instead
+	{ "rhotic",       tPHONEME_FLAG, phRHOTIC },
 	{ "nonsyllabic",  tPHONEME_FLAG, phNONSYLLABIC }, // TODO (deprecated): use 'nsy' instead
 	{ "lengthenstop", tPHONEME_FLAG, phLENGTHENSTOP },
 	{ "nopause",      tPHONEME_FLAG, phNOPAUSE },

src/libespeak-ng/phoneme.c

 	case vzd:
 	case fzd:
 	case nzd:
-		// Not supported by eSpeak.
-		break;
 	case rzd:
-		phoneme->phflags |= phRHOTIC;
+		// Not supported by eSpeak.
 		break;
 	// tongue root
 	case atr: