Make DOGLCD merge neater.

Marlin/Marlin.pde

   #elif defined(LCD_I2C_TYPE_MCP23017) || defined(LCD_I2C_TYPE_MCP23008)
     #include <Wire.h>
     #include <LiquidTWI2.h>
-  #else
-    #include <LiquidCrystal.h>
-  #endif
-  #ifdef DOGLCD
+  #elif defined(DOGLCD)
     #include <U8glib.h> // library for graphics LCD by Oli Kraus (https://code.google.com/p/u8glib/)
   #else
     #include <LiquidCrystal.h> // library for character LCD