Also update our database when we get an invalid image.
Also update our database when we get an invalid image.

Note : removed the logging actions, as responseData is often nil, which caused assertion failures.
ViennaRSS/vienna-rss,ViennaRSS/vienna-rss,dak180/vienna,Eitot/vienna-rss,Eitot/vienna-rss,Feitianyuan/vienna-rss,lapcat/vienna-rss,tothgy/vienna-rss,Eitot/vienna-rss,Feitianyuan/vienna-rss,Feitianyuan/vienna-rss,ViennaRSS/vienna-rss,lapcat/vienna-rss,tothgy/vienna-rss,josh64x2/vienna-rss,barijaona/vienna-rss,josh64x2/vienna-rss,barijaona/vienna-rss,ViennaRSS/vienna-rss,barijaona/vienna-rss,Eitot/vienna-rss,dak180/vienna,barijaona/vienna-rss,dak180/vienna,iamjasonchoi/vienna-rss,iamjasonchoi/vienna-rss,aidanamavi/vienna-rss,josh64x2/vienna-rss,tothgy/vienna-rss,josh64x2/vienna-rss,lapcat/vienna-rss,barijaona/vienna-rss,josh64x2/vienna-rss,tothgy/vienna-rss,aidanamavi/vienna-rss,lapcat/vienna-rss,ViennaRSS/vienna-rss,dak180/vienna,aidanamavi/vienna-rss,iamjasonchoi/vienna-rss