Display tunnel description on IPsec widget

There was not even code to attempt to display the description.
Also, when I first created a phase1 and there were no phase2 yet, the widget spat out the warning for the line:
foreach ($config['ipsec']['phase2'] as $ph2ent){ ...
So I enclosed that in a block:
if (isset($config['ipsec']['phase2'])) { ... }
Tabbing that block in makes the diff look big when there really is little change - a diff ignoring spacing will look much nicer!
Merge pull request #1402 from phil-davis/patch-1