Source json.h non-locally.

Change-Id: Ia42c41fde74596b394a1f7ae0021f1a5510991a8
diff --git a/cper-parse.i b/cper-parse.i
index fa12bc3..7ba1da4 100644
--- a/cper-parse.i
+++ b/cper-parse.i
@@ -1,7 +1,7 @@
 %module cperparse
 %{
     #include "cper-parse.h"
-    #include "json.h"
+    #include <json.h>
     #include <stdio.h>
 %}