remove "#include <unistd.h> from rdoff directory - two places - it annoyed Windows users and seems unneeded

rdoff/rdflib.c

@@ -25,7 +25,6 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <errno.h>
 #include <string.h>
 #include <inttypes.h>

rdoff/rdlar.c

@@ -8,7 +8,6 @@
 #include <ctype.h>
 #include <stdarg.h>
 #include <string.h>
-#include <unistd.h>
 #include <errno.h>
 #include <time.h>
 #include <sys/types.h>