CP-4318: Handle v6d not running when creating software_version

Signed-off-by: John Else <john.else@citrix.com>

ocaml/xapi/create_misc.ml

@@ -381,9 +381,17 @@ let make_packs_info () =
 let make_software_version () =
 	let option_to_list k o = match o with None -> [] | Some x -> [ k, x ] in
 	let info = read_localhost_info () in
-	let v6_version = V6client.get_version "make_software_version" in
+	let v6_version =
+		(* Best-effort attempt to read the date-based version from v6d *)
+		try
+			match V6client.get_version "make_software_version" with
+			| "" -> []
+			| dbv -> ["dbv", dbv]
+		with Api_errors.Server_error (code, []) when code = Api_errors.v6d_failure ->
+			[]
+	in
 	Xapi_globs.software_version @
-	(if v6_version = "" then [] else ["dbv", v6_version]) @
+	v6_version @
 	[
 		"xapi", get_xapi_verstring ();
 		"xen", info.xen_verstring;