webadmin: fix Maintenance Hosts dialog missing padding

Maintenance Hosts dialog missing left and right padding, on the second paragraph.
Fixed.

Change-Id: I66b05612c083228a8e7069282a167548ed39c92e
Bug-Url: https://bugzilla.redhat.com/1139930
Signed-off-by: Greg Sheremeta <gshereme@redhat.com>