Merge pull request #4140 from thinkyhead/rc_button_reliability

Always do a brief delay in `lcd_quick_feedback`

Marlin/ultralcd.cpp

       lcd.buzz(LCD_FEEDBACK_FREQUENCY_DURATION_MS, LCD_FEEDBACK_FREQUENCY_HZ);
     #elif PIN_EXISTS(BEEPER)
       buzzer.tone(LCD_FEEDBACK_FREQUENCY_DURATION_MS, LCD_FEEDBACK_FREQUENCY_HZ);
-    #else
-      delay(LCD_FEEDBACK_FREQUENCY_DURATION_MS);
     #endif
+    delay(10); // needed for buttons to settle
   }
 
   /**