Mark all days NNY, instead of up to last day.

The game wasn't detecting that all days had
been played.  This fixes that by filling
in all the days, rather then just up to
the last day of the month.

play.cpp

@@ -1626,8 +1626,8 @@ std::unique_ptr<door::Screen> PlayCards::make_calendar() {
   }
 #endif
 
-  // mark days ahead as NNY.
-  for (int d = 0; d < month_last_day; ++d) {
+  // mark all days ahead as NNY.
+  for (int d = 0; d < 31; ++d) {
     if (this_day + play_days_ahead - 1 < d) {
       calendar_day_status[d] = 3;
     }