[UI] problem of d&d when copy of UI command is disabled

[nao-pon]

Describe the bug
Drag and drop is not possible when copy of UI command is disabled.

To Reproduce
Steps to reproduce the behavior:

bootCallback: function (fm) {
    delete fm.commands.copy;
}

1. I can't drag and drop.

Expected behavior
If the copy command is disabled but the cut command is enabled, you should be able to drag and drop.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows10
• Browser Chrome
• Version 91

Additional context
See #3280 PR.