Fix to a security issue
Fix to a security issue

- as reported by RichieB2B
- Trying to view an event that doesn't exist and one that the user has no access to resulted in different error messages

Rafiot/MISP,SteveClement/MISP,RichieB2B/MISP,FloatingGhost/MISP,TheDr1ver/MISP,FIRSTdotorg/MISP,MISP/MISP,cristianbell/MISP,FloatingGhost/MISP,cristianbell/MISP,crruthe/MISP,crruthe/MISP,Rafiot/MISP,FloatingGhost/MISP,MISP/MISP,SteveClement/MISP,aaronkaplan/MISP,Rafiot/MISP,SteveClement/MISP,MISP/MISP,devnull-/MISP,RichieB2B/MISP,TheDr1ver/MISP,FloatingGhost/MISP,cristianbell/MISP,cristianbell/MISP,aaronkaplan/MISP,TheDr1ver/MISP,Rafiot/MISP,devnull-/MISP,MISP/MISP,SteveClement/MISP,SteveClement/MISP,FIRSTdotorg/MISP,devnull-/MISP,FIRSTdotorg/MISP,crruthe/MISP,devnull-/MISP,FIRSTdotorg/MISP,TheDr1ver/MISP,aaronkaplan/MISP,RichieB2B/MISP,aaronkaplan/MISP,RichieB2B/MISP,MISP/MISP,crruthe/MISP