- First replacement of xyssl by polarssl where needed

diff --git a/include/polarssl/certs.h b/include/polarssl/certs.h
index 7b91baf..6bc74bf 100644
--- a/include/polarssl/certs.h
+++ b/include/polarssl/certs.h
@@ -1,8 +1,8 @@
 /**
  * \file certs.h
  */
-#ifndef XYSSL_CERTS_H
-#define XYSSL_CERTS_H
+#ifndef POLARSSL_CERTS_H
+#define POLARSSL_CERTS_H
 
 #ifdef __cplusplus
 extern "C" {