Fix compiler warning:

In file included from sketch/ConfigurationStore.cpp:4:0:
sketch/ultralcd.h:12:14: warning: 'void lcd_language_menu()' declared 'static' but never defined [-Wunused-function]
  static void lcd_language_menu();

Firmware/ultralcd.cpp

@@ -209,6 +209,7 @@ static const char* lcd_display_message_fullscreen_nonBlocking_P(const char *msg,
 
 /* Different menus */
 static void lcd_status_screen();
+static void lcd_language_menu();
 #ifdef ULTIPANEL
 extern bool powersupply;
 static void lcd_main_menu();

Firmware/ultralcd.h

@@ -9,8 +9,6 @@ extern int lcd_printf_P(const char* format, ...);
 
 #ifdef ULTRA_LCD
 
-	static void lcd_language_menu();
-
   void lcd_update(uint8_t lcdDrawUpdateOverride = 0, bool forceRedraw = false);
   // Call with a false parameter to suppress the LCD update from various places like the planner or the temp control.
   void lcd_update_enable(bool enable);