Fix signin issue with numeric usernames
Fix signin issue with numeric usernames

Fix issue with numeric usernames upon signin, where an incorrect details
message would always be returned (from
5bdfaaf7f56e13874528c184c3c1abab8431aab0 on master)

NamelessMC/Nameless,NamelessMC/Nameless,NamelessMC/Nameless,NamelessMC/Nameless