Fix display of Y on Graphical LCD

Marlin/src/lcd/dogm/status_screen_DOGM.h

     #define XYZ_FRAME_HEIGHT INFO_FONT_HEIGHT + 1
   #endif
 
-  static char xstring[5], ystring[5], zstring[7];
+  static char xstring[5], ystring[5], zstring[8];
   #if ENABLED(FILAMENT_LCD_DISPLAY)
     static char wstring[5], mstring[4];
   #endif