fix: fixes the callback query checks

[paul-vd]

The previous if statement resulted in the emailRedirectLogin being called without magic link being defined. eg;

if(magic && router.query.provider) return finishSocialLogin()
else return finishEmailRedirectLogin()

I should instead read:

if(magic){
   if(router.query.provider) return finishSocialLogin()
   else return finishEmailRedirectLogin()
}