fix file name for web remote log files

The key name was not being sufficiently escaped, although it didn't break
anything due to luck. Switch to properly escaped key names for the log
filename, with a fallback to the buggy old name.

Remote/Web.hs

@@ -67,10 +67,17 @@ gen r _ _ =
 {- The urls for a key are stored in remote/web/hash/key.log 
  - in the git-annex branch. -}
 urlLog :: Key -> FilePath
-urlLog key = "remote/web" </> hashDirLower key </> show key ++ ".log"
+urlLog key = "remote/web" </> hashDirLower key </> keyFile key ++ ".log"
+oldurlLog :: Key -> FilePath
+{- A bug used to store the urls elsewhere. -}
+oldurlLog key = "remote/web" </> hashDirLower key </> show key ++ ".log"
 
 getUrls :: Key -> Annex [URLString]
-getUrls key = currentLog (urlLog key)
+getUrls key = do
+	us <- currentLog (urlLog key)
+	if null us
+		then currentLog (oldurlLog key)
+		else return us
 
 {- Records a change in an url for a key. -}
 setUrl :: Key -> URLString -> LogStatus -> Annex ()