postgresql: add man output

Mic92 · Mic92 · commit 029125b973e4 · 2017-05-20T07:07:12.000+01:00
the doc output is not installed by default (where manpages where included). This leads to manpages not present when enabling postgresql service. fixes #25928
diff --git a/pkgs/servers/sql/postgresql/default.nix b/pkgs/servers/sql/postgresql/default.nix
@@ -11,7 +11,7 @@ let
       inherit sha256;
     };
 
-    outputs = [ "out" "lib" "doc" ];
+    outputs = [ "out" "lib" "doc" "man" ];
     setOutputFlags = false; # $out retains configureFlags :-/
 
     buildInputs =
