[Wireguard] Add Button has btn-default instead of btn-primary

[KluthR]

Hey,

OpnSense 24.7_9

too small for a "bug" report. Maybe some dev reads this:

Every Plus (Add) button has the CSS class "primary" (orange). But the Wireguard -> Instances (and Peers) Button has default (white) color. This does not align with the rest.

Maybe someone can change this for future versions? :)

[Monviech (Cedrik)]

Thank you for noticing.

https://github.com/opnsense/core/pull/7733