Fix ghc-7.10 warnings in ranking/votes feature
Fix ghc-7.10 warnings in ranking/votes feature

tkvogt/hackage-server,agrafix/hackage-server,dzackgarza/hackage-server,edsko/hackage-server,chrisdotcode/hackage-server,ocharles/hackage-server,agrafix/hackage-server,chrisdotcode/hackage-server,ocharles/hackage-server,edsko/hackage-server,erantapaa/hackage-server,erantapaa/hackage-server,dzackgarza/hackage-server,tkvogt/hackage-server