Border-radius applied incorrectly in optgroup selects

[sbine]

The .selectboxit-option-first class causes a border-radius to be applied to the top of the first <option> even when there's an optgroup label before it.
See it in action in the demo.

As a side note/suggestion, I also added the following styles to give the select box a bit more breathing room:

.selectboxit-container .selectboxit {
    padding-left: 5px;
}
.selectboxit-optgroup-header {
    padding: 5px;
}

Thank you once again for sharing this great plugin.

[gfranko]

Thank you for reporting this issue! The first option no longer has a border radius if it is within an optgroup. Let me know if you find any other issues!