add `Show/hide ignore local changes flagged files` in Log Dialog

What steps will reproduce the problem?

1. I use the Log Dialog very frequently.
2. When I select Working tree changes, I can do skip worktree with the bottom pane's context menu, but can not undo it in the Log Dialog easily.

What is the expected output? What do you see instead?

• Add Show/hide ignore local changes flagged files to the context menu of the entry Working tree changes.
• Or add a checkbox under the bottom pane when the entry Working tree changes is selected, like the Check for Modifications Dialog,.

What version of TortoiseGit and Git are you using? On what operating system?

• TortoiseGit 2.4.0.2
• Git 2.12.2.windows.2
• Windows 7

Please provide any additional information below.

(none)