Merge pull request #4572 from thinkyhead/rc_digital_clock_100h

Show up to 99:59 in digital time

Marlin/Marlin_main.cpp

     UNUSED(lcd_msg);
   #endif
 
-  for (int i = 5; i--;) delay(100); // Wait a short time
+  delay(500); // Wait a short time
 
   cli(); // Stop interrupts
   thermalManager.disable_all_heaters();

Marlin/SanityCheck.h

 /**
  * emergency-command parser
  */
-#if ENABLED(EMERGENCY_PARSER) && ENABLED(USBCON)
+#if ENABLED(EMERGENCY_PARSER) && defined(USBCON)
   #error "EMERGENCY_PARSER does not work on boards with AT90USB processors (USBCON)."
 #endif

Marlin/duration_t.h

    *  1193046:59
    */
   void toDigital(char *buffer) const {
-    int h = this->hour() % 24,
+    int h = this->hour(),
         m = this->minute() % 60;
 
     sprintf_P(buffer, PSTR("%02i:%02i"), h, m);