fix wrong kind in warning for missing label

Signed-off-by: Paul-Elliot <peada@free.fr>

Author: panglesd

src/xref2/ref_tools.ml

@@ -349,7 +349,7 @@ module L = struct
             when name = LabelName.to_string name' ->
               Ok (`Identifier label)
           | _ -> find tl)
-      | [] -> Error (`Find_by_name (`Page, name))
+      | [] -> Error (`Find_by_name (`Label, name))
     in
     find p.Odoc_model.Lang.Page.content
 

test/xref2/references_to_pages.t/run.t

@@ -2,7 +2,7 @@
 
   $ compile p.mld good_references.mli bad_references.mli
   File "bad_references.mli", line 6, characters 42-69:
-  Warning: Failed to resolve reference unresolvedroot(p).not_found Couldn't find page "not_found"
+  Warning: Failed to resolve reference unresolvedroot(p).not_found Couldn't find label "not_found"
   File "bad_references.mli", line 4, characters 20-37:
   Warning: Failed to resolve reference unresolvedroot(not_found) Couldn't find page "not_found"