Disable TACH_1 fancheck on selftest

Firmware/ultralcd.cpp

@@ -6370,12 +6370,14 @@ static bool fan_error_selftest()
         return 1;
     }
 #endif
+ /*
 #ifdef TACH_1
     if (fan_speed[1] <= 20) { //print fan error
         LCD_ALERTMESSAGERPGM(MSG_FANCHECK_PRINT);
         return 1;
     }
 #endif
+*/
 #endif //FANCHECK
     return 0;
 }