webadmin: Fix findbugs 'ignore java.lang.Exception' warning

DynamicTabContainerPresenter.setInSlot method override repeats
some code from superclass method (TabContainerPresenter.setInSlot)
simply because it doesn't allow easy extension of its logic.

This patch fixes 'ignore java.lang.Exception' findbugs warning
by logging the exception via client-side logger infrastructure.

Change-Id: I414216bdbf0419862a6beeebf037ec559d608290
Signed-off-by: Vojtech Szocs <vszocs@redhat.com>