webadmin: Fix import gluster hosts popup layout

When the hostname is too big, the table width
goes outside of the popup. This is fixed now.

Change-Id: I2d069b3227d2a504d339105d658890bd742924f7
Bug-Url: https://bugzilla.redhat.com/881856
Signed-off-by: Kanagaraj M <kmayilsa@redhat.com>