Make tron follow TRON_NOGROW , thought that was in there.... (github edit because cate is annoying me)

src/elements/tron.c

@@ -47,6 +47,7 @@ int new_tronhead(int x, int y, int i, int direction)
 		return -1;
 	if (parts[i].life >= 100) // increase tail length
 	{
+		if (!(parts[i].tmp&TRON_NOGROW))
 			parts[i].tmp2++;
 		parts[i].life = 5;
 	}