Fixes duplicate panels.

[mxm1070]

I was testing the new pages feature of the library and I noticed that if you add panels with the same name, but different fields it combines the fields, but also duplicates the panels. This fixes the panel duplication.

NovaSettings::addSettingsFields([
    new Panel('Wrong', [
        Text::make('A', 'a'),
    ])
], [], 'Test');

NovaSettings::addSettingsFields([
    new Panel('Wrong', [
        Text::make('B', 'b'),
    ])
], [], 'Test');

NovaSettings::addSettingsFields([
    new Panel('Correct', [
        Text::make('C', 'c'),
    ])
], [], 'Test');

Before:

After:

[Tarpsvo]

Awesome! Thanks for helping out. :) I'll be releasing it in a second.

[Tarpsvo]

Released in version 3.0!