DvDWriteNow 1.5.12 SP2 setup should not allow to open a SysMenu

When I tested the fix for CORE-15669 I made an interesting observation:

Reproduction steps

• Open DvDWriteNow 1.5.12 SP2 setup from rapps
• try to invoke the sysmenu

Observed result
0.4.15-dev-2620-g5ce9e2e_withPR3700.webm
0.4.15-dev-2620-g5ce9e2e_withPR3700.log
As you can see, ros is not properly capable to invoke "restore" and "minimize" for this setup in an alternating way, and for a short moment I did expect this to be an error, but when I checked how 2k3sp2 does behave, I did realize

Expected result
surprisingly 2k3sp2 does completely forbid that fancy setup to show a sysmenu at all
2k3sp2_doesNotallowToOpenTheSysMenuHere.webm
I guess it would be clever for ros to do the same!