Fix invalid user (#4081)
Fix invalid user (#4081)

#fix https://github.com/FreshRSS/FreshRSS/issues/4080
Initialise the default user to be able to display the error page
FreshRSS/FreshRSS,Alkarex/FreshRSS,aledeg/FreshRSS,FreshRSS/FreshRSS,Alkarex/FreshRSS,aledeg/FreshRSS,Alkarex/FreshRSS,Alkarex/FreshRSS,FreshRSS/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,FreshRSS/FreshRSS