only include strings.h if it is actually preent

src/logging.c

@@ -20,11 +20,16 @@
  *
  */
 
+#include "../config.h"
+
 #include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+
+#ifdef HAVE_STRINGS_H
 #include <strings.h>
+#endif
 #include <time.h>
 #include <errno.h>