build BUGFIX missing C++ include macro

Fixes #132
diff --git a/src/netconf.h b/src/netconf.h
index 73152db..ce1642d 100644
--- a/src/netconf.h
+++ b/src/netconf.h
@@ -15,12 +15,12 @@
 #ifndef NC_NETCONF_H_
 #define NC_NETCONF_H_
 
-#include <time.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#include <time.h>
+
 /**
  * @addtogroup misc
  * @{