webadmin,userportal: Fix action table element IDs

This patch fixes a problem in AbstractActionTable which uses
two table widgets internally (optional header + main table).

Since both above mentioned table widgets are now derived from
ColumnResizeCellTable, and sice column definition objects are
shared between both tables, we must not set element IDs for
the optional header table.

Change-Id: I318338a8e92b3967b4ce40ac288add846f0a1444
Bug-Url: https://bugzilla.redhat.com/960519
Signed-off-by: Vojtech Szocs <vszocs@redhat.com>