Disable print fan check in self test

Print fans's third pin is no longer connected for monitoring RPM.

Firmware/ultralcd.cpp

@@ -7414,7 +7414,7 @@ bool lcd_selftest()
 	{
 		lcd_selftest_error(TestError::ExtruderFan, "", "");
 	}
-
+/*
 	if (_result)
 	{
 		_progress = lcd_selftest_screen(TestScreen::PrintFan, _progress, 3, true, 2000);
@@ -7454,6 +7454,7 @@ bool lcd_selftest()
 			lcd_selftest_error(TestError::SwappedFan, "", "");
 		}
 	}
+*/
 
 	if (_result)
 	{