fix fastDebug to check if debugging is actually enabled

Had to add to AnnexRead an indication of whether debugging is enabled.

Could have just made setupConsole not install a debug output action that
outputs, and have enableDebug be what installs that, but then in the
common case where there is no debug selector, and so all debug output is
selected, it would run the debug output action every time, which entails
an IORef access. Which would make fastDebug too slow..

Remote/Helper/Ssh.hs

@@ -59,7 +59,7 @@ git_annex_shell cs r command params fields
 	dir = Git.repoPath r
 	shellcmd = "git-annex-shell"
 	getshellopts = do
-		debugenabled <- annexDebug <$> Annex.getGitConfig
+		debugenabled <- Annex.getRead Annex.debugenabled
 		let params' = if debugenabled
 			then Param "--debug" : params
 			else params