Linux build fix

createuniverses · createuniverses · commit a3332f938ebc · 2016-05-13T11:18:52.000+10:00
The header unistd.h used to be included by one of the FICL headers.
diff --git a/luaCB.h b/luaCB.h
@@ -30,6 +30,8 @@
 #include <sys/ioctl.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+
+#include <unistd.h>
 #endif
 
 #include "luaCallbacks.h"
