webadmin: VMs tab heading "Time executing" truncated in display

In es_ES locale the VMs tab column header
"Time Executing" is truncated. The column width
is too small to accomodate the text.

Change-Id: I69d8f94931693600431a2a3fc998c9581cb2a5b2
Bug-Url: https://bugzilla.redhat.com/1009757
Signed-off-by: Ravi Nori <rnori@redhat.com>