[primus] Fix return type of method `open` on the socket instance (#45063)
[primus] Fix return type of method `open` on the socket instance (#45063)

* Added missing method 'open' to Primus.Socket

* Fixed spacing

* Change return type of method `open`

* Fix return type of method `open`
georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,dsebastien/DefinitelyTyped,dsebastien/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped