Embed protocol data also for Windows version of trash ioslave.

Summary:
trash:/-protocol is currently broken on Windows: https://bugs.kde.org/show_bug.cgi?id=414430

The cause seems to be that the trash-protocol meta data is not installed on Windows: The protocol is
built from entirely separate sources on Windows, and the Windows-version was forgotten in this commit:
https://cgit.kde.org/kio.git/commit/src/ioslaves/trash/CMakeLists.txt?id=a3fee508c6c42b1b86155719e38a84b1128360eb

Test Plan: This patch fixes the problem for me on Windows 8.1, MinGW64

Reviewers: cullmann, vonreth

Reviewed By: cullmann

Subscribers: kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D26365