Communicator not destroyed in cpp98 Freeze/backup demo on Windows10

[InsertCreativityHere]

Get the following error when running the cpp98 Freeze/backup demo in release mode. Debug mode appears fine:

error: communicator not destroyed during global destruction.
restarting client... (client)

Seems the communicator isn't properly cleaned up when the client is killed on windows10_vs2013 and vs2015.

*** running demo 1/9 in C:\Users\vagrant\workspace\freeze-dist\3.7\dist-utils\demoscript\freeze\cpp98\Freeze\backup
*** configuration: --x86 --mode release --fast --debug
*** demo started: 09/18/19 10:54:45
[ running demos from C:\Users\vagrant\workspace\freeze-dist\3.7\dist-utils\build\freeze\builds\freeze-demos-v140-x86-default\demos]
cleaning databases... ok
(client)
populating map... ok
performing full backup... (backup.bat full)
ok
sleeping 5s... ok
performing incremental backup... (backup.bat incremental)
ok
sleeping 30s... ok
killing client with SIGTERM... ok
Client output:
Read 09/18/19 10:54:45.976 in all records; updating with 09/18/19 10:54:46.268 ... done
    ...*nothing important*
Read 09/18/19 10:55:28.939 in all records; updating with 09/18/19 10:55:28.980 ... done
!! 09/18/19 10:55:29.060 error: communicator not destroyed during global destruction.
restarting client... (client)
ok
sleeping 5s... ok
killing client with SIGTERM... ok
Restarted client output:
Read 09/18/19 10:54:56.282 in all records; updating with 09/18/19 10:55:30.321 ... done
    ...*nothing important*
!! 09/18/19 10:55:35.323 error: communicator not destroyed during global destruction.

Example log file: "https://jenkins.testing.zeroc.com/job/freeze-dist/job/3.7/238/artifact/test-testoutput-windows-windows10_vs2013.log" on lines 5095 and 6680

[bernardnormier]

This demo simulates a crash so this is expected.