Use system getopt instead of custom one
https://bugs.gentoo.org/944937

--- a/Makefile
+++ b/Makefile
@@ -24,8 +24,8 @@ CC = gcc
 export CCOPTS CC FORMATDEFS
 
 LISPREADER_OBJS = lispreader.o pools.o allocator.o
-OBJS = metapixel.o vector.o zoom.o $(LISPREADER_OBJS) getopt.o getopt1.o
-CONVERT_OBJS = convert.o $(LISPREADER_OBJS) getopt.o getopt1.o
+OBJS = metapixel.o vector.o zoom.o $(LISPREADER_OBJS)
+CONVERT_OBJS = convert.o $(LISPREADER_OBJS)
 IMAGESIZE_OBJS = imagesize.o
 
 all : metapixel metapixel.1 convert metapixel-imagesize