mod_linkinfo: remove wrong twitter assertion
mod_linkinfo: remove wrong twitter assertion

their API can return multiple extended_entities with the
same url, which would trigger the assert

baines/insobot,Chronister/insobot,insofaras/insobot,baines/insobot,insofaras/insobot,baines/insobot,insofaras/insobot,Chronister/insobot,Chronister/insobot