add #include <unistd.h> to declare the timeval structure

In file included from ifdwrapper.c:31:
utils.h:26: warning: ‘struct timeval’ declared inside parameter list
utils.h:26: warning: its scope is only this definition or declaration, which is probably not what you want


git-svn-id: svn:https://anonscm.debian.org/svn/pcsclite/trunk/PCSC@4630 0ce88b0d-b2fd-0310-8134-9614164e65ea

src/ifdwrapper.c

@@ -17,6 +17,7 @@
  */
 
 #include <errno.h>
+#include <unistd.h>
 #include "config.h"
 #include "misc.h"
 #include "pcscd.h"