fix(authentication-oauth): Updated typings for projects with strictNullChecks (#1941)
fix(authentication-oauth): Updated typings for projects with strictNullChecks (#1941)

Co-authored-by: David Luecke <75efc9077f4d7065d75a3a4c365ef7044bfdf852@neyeon.com>
feathersjs/feathers,feathersjs/feathers,feathersjs/feathers