Adapt code to optparse-applicative 0.18.1 and later.

optparse-applicative switched to the 'prettyprinter' library in its latest
release, which means the 'H.text' function has disappeared. Instead, 'H.pretty'
can be used to convert all 'Pretty a' types into a renderable document.

CmdLine.hs

@@ -116,7 +116,7 @@ parseCmd progname progdesc allargs allcmds getparser =
 		<*> getparser c
 		<*> parserAnnexOptions (cmdannexoptions c)
 	synopsis n d = n ++ " - " ++ d
-	intro = mconcat $ concatMap (\l -> [H.text l, H.line])
+	intro = mconcat $ concatMap (\l -> [H.pretty l, H.line])
 		(synopsis progname progdesc : commandList allcmds)
 
 {- Selects the Command that matches the subcommand name.

git-annex.cabal

@@ -311,7 +311,7 @@ Executable git-annex
   Build-Depends:
    base (>= 4.11.1.0 && < 5.0),
    network-uri (>= 2.6),
-   optparse-applicative (>= 0.14.1),
+   optparse-applicative (>= 0.18.1),
    containers (>= 0.5.8),
    exceptions (>= 0.6),
    stm (>= 2.3),