Aplied HAS_LCD_CONTRAST also to Marlin_main.cpp

and cleaned typo.

Marlin/Conditionals.h

   #ifdef DOGLCD
     #define HAS_LCD_CONTRAST
     #ifdef U8GLIB_ST7920
-      #undefine HAS_LCD_CONTRAST
+      #undef HAS_LCD_CONTRAST
     #endif
   #endif
 

Marlin/Marlin_main.cpp

 
 #endif // CHDK || PHOTOGRAPH_PIN
 
-#ifdef DOGLCD
+#ifdef HAS_LCD_CONTRAST
 
   /**
    * M250: Read and optionally set the LCD contrast
     SERIAL_EOL;
   }
 
-#endif // DOGLCD
+#endif // HAS_LCD_CONTRAST
 
 #ifdef PREVENT_DANGEROUS_EXTRUDE
 
           break;
       #endif // CHDK || PHOTOGRAPH_PIN
 
-      #ifdef DOGLCD
+      #ifdef HAS_LCD_CONTRAST
         case 250: // M250  Set LCD contrast value: C<value> (value 0..63)
           gcode_M250();
           break;
-      #endif // DOGLCD
+      #endif // HAS_LCD_CONTRAST
 
       #ifdef PREVENT_DANGEROUS_EXTRUDE
         case 302: // allow cold extrudes, or set the minimum extrude temperature