ns_mitm: update to support new 19.0.0 command

libraries/libstratosphere/include/stratosphere/hos/hos_types.hpp

@@ -84,6 +84,7 @@ namespace ams::hos {
         Version_17_0_1  = ::ams::TargetFirmware_17_0_1,
         Version_18_0_0  = ::ams::TargetFirmware_18_0_0,
         Version_18_1_0  = ::ams::TargetFirmware_18_1_0,
+        Version_19_0_0  = ::ams::TargetFirmware_19_0_0,
 
         Version_Current = ::ams::TargetFirmware_Current,