Fix warnings

include/fmt/chrono.h

@@ -548,14 +548,14 @@ struct chrono_formatter {
   void on_12_hour(numeric_system ns) {
     if (ns == numeric_system::standard) return write(hour12(), 2);
     auto time = tm();
-    time.tm_hour = hour12();
+    time.tm_hour = to_int(hour12());
     format_localized(time, "%OI");
   }
 
   void on_minute(numeric_system ns) {
     if (ns == numeric_system::standard) return write(minute(), 2);
     auto time = tm();
-    time.tm_min = minute();
+    time.tm_min = to_int(minute());
     format_localized(time, "%OM");
   }
 
@@ -570,7 +570,7 @@ struct chrono_formatter {
       return;
     }
     auto time = tm();
-    time.tm_sec = second();
+    time.tm_sec = to_int(second());
     format_localized(time, "%OS");
   }