tmf: Don't change event table selection on right-click

tmf: Don't change event table selection on right-click

When right-clicking on a item that is within the selection range, the
selection should not be changed to the clicked item. This would prevent
any context menu actions from operating on a selection range.

Change-Id: I3eb06471a3dd80cc3683fcdc965fd36a67ce86a8
Signed-off-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-on: https://git.eclipse.org/r/15298
Tested-by: Hudson CI
Reviewed-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
IP-Clean: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Tested-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>