Fix 6d6e64b1f0: Road stop properties 0x13/0x14 were not skipped properly. (#14567)

These properties where changed to be variable length for consistency, but ignoring them treated them as fixed length.

src/newgrf/newgrf_act0_roadstops.cpp

@@ -51,9 +51,7 @@ static ChangeInfoResult IgnoreRoadStopProperty(uint prop, ByteReader &buf)
 
 		case 0x13:
 		case 0x14:
-			buf.ReadWord();
-			buf.ReadWord();
-			buf.ReadWord();
+			buf.Skip(buf.ReadExtendedByte());
 			break;
 
 		case 0x16: // Badge list