Update admin/assets/css/admin-style.css

Hopefully it's the last patch to improve padding/margin. This time around multi checkboxes and radios. Checked on all major browsers (ff, safari, opera and ie8). In ie8 there is slight misalignment but not due to patch (it was also visible in previous versions of smof)
Merge pull request #163 from partnuz/patch-3

Update admin/assets/css/admin-style.css