hi useing scrollbar to locate the #if defined for your LCD screen that you selected
add the following two lines before the #endif statement
#define ENCODER_PULSES_PER_STEP 4
#define ENCODER_STEPS_PER-MENU_ITEM 1
should look like this
#if defined(REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER)
#define DOGLCD
#define U8GLIB_ST7920
#define REPRAP_DISCOUNT_SMART_CONTROLLER
#define ENCODER_PULSES_PER_STEP 4
#define ENCODER_STEPS_PER_MENUE_ITEM 1
#endif