Don't let the app crash when there is no access_token in oauth2 response.
Don't let the app crash when there is no access_token in oauth2 response.

dongri/OAuthSwift,dongri/OAuthSwift,fewspider/OAuthSwift,matteobruni/OAuthSwift,OAuthSwift/OAuthSwift,olivier38070/OAuthSwift,ianbytchek/OAuthSwift,ianbytchek/OAuthSwift,olivier38070/OAuthSwift,OAuthSwift/OAuthSwift,matteobruni/OAuthSwift,fewspider/OAuthSwift,back2mach/OAuthSwift,back2mach/OAuthSwift