sort languages by display value

Change-Id: I79d58fd680dd04161b89d42fed04a86a931defd3
Signed-off-by: Xuefer <xuefer@gmail.com>
diff --git a/gui/pages.hpp b/gui/pages.hpp
index cf1afa1..927f3fc 100644
--- a/gui/pages.hpp
+++ b/gui/pages.hpp
@@ -34,6 +34,11 @@
 	std::string displayvalue;
 };
 
+inline bool operator < (const language_struct& language1, const language_struct& language2)
+{
+	return language1.displayvalue < language2.displayvalue;
+}
+
 extern std::vector<language_struct> Language_List;
 
 // Utility Functions