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/identity-certificate.cpp b/src/security/identity-certificate.cpp
index 334172e..44d6588 100644
--- a/src/security/identity-certificate.cpp
+++ b/src/security/identity-certificate.cpp
@@ -6,7 +6,9 @@
  * See COPYING for copyright and distribution information.
  */
 
-#include "security/identity-certificate.hpp"
+#include "common.hpp"
+
+#include "identity-certificate.hpp"
 
 using namespace std;