Fallback when GUID is empty
Fallback when GUID is empty

https://github.com/FreshRSS/FreshRSS/issues/1482

Alkarex/FreshRSS,FreshRSS/FreshRSS,romibi/FreshRSS,FreshRSS/FreshRSS,Alkarex/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,FreshRSS/FreshRSS,aledeg/FreshRSS,Alkarex/FreshRSS,romibi/FreshRSS,romibi/FreshRSS,Alkarex/FreshRSS,marienfressinaud/FreshRSS,marienfressinaud/FreshRSS,romibi/FreshRSS,marienfressinaud/FreshRSS,marienfressinaud/FreshRSS,FreshRSS/FreshRSS