build: Experimental support to build using precompiled headers

This type of build needs to be explicitly enabled using --with-pch
configure option.

Change-Id: I02dc304187d54c3cf40f1d51b1b11b21f868e225
diff --git a/src/security/certificate.cpp b/src/security/certificate.cpp
index 3a3b224..3778a80 100644
--- a/src/security/certificate.cpp
+++ b/src/security/certificate.cpp
@@ -8,7 +8,7 @@
 
 #include "common.hpp"
 
-#include "security/certificate.hpp"
+#include "certificate.hpp"
 
 #include "../util/logging.hpp"
 #include "../util/time.hpp"