core: restored USER_AGENT and SERVER_HDR defines

- they were changed by accident by previous commit

config.h

@@ -87,11 +87,11 @@
 #define CONTENT_LENGTH "Content-Length: "
 #define CONTENT_LENGTH_LEN (sizeof(CONTENT_LENGTH)-1)
 
-#define USER_AGENT "User-Agent: OpenXg SIP Proxy "\
+#define USER_AGENT "User-Agent: " NAME \
 		" (" VERSION " (" ARCH "/" OS_QUOTED "))"
 #define USER_AGENT_LEN (sizeof(USER_AGENT)-1)
 
-#define SERVER_HDR "Server: OpenXg SIP Proxy "\
+#define SERVER_HDR "Server: " NAME \
 		" (" VERSION " (" ARCH "/" OS_QUOTED "))"
 #define SERVER_HDR_LEN (sizeof(SERVER_HDR)-1)