hidden dock doesn't stay hidden on project load

[mccrabney]

1- create project
2- create floating dock with something in it (example: a script that has a GUI that must stay open in order to keep the script running, but that you don't need to see in order to use)
3- hide the dock
4- save the project
5- close REAPER
6- reopen REAPER and reopen project
7- ISSUE: dock is no longer hidden.

NOTE: in step 5, if you just reopen the project rather than closing REAPER, the dock stays hidden. this is the desired behavior.

[mccrabney]

solved with window screenset loaded on REAPER start.