copr: fix the Pulp redirect script for devel repositories

We dont have a ticket but the problem was discovered on the @asahi/kernel
project and reported by @jannau. The use-case is

> We use the devel repositories for fedora asahi remix to have a bodhi like
> experience for copr projects

and technically, they enable the repositores on user machines like this:

26cab83/f/asahi-repos.spec (_149-160)

roles/copr/backend/templates/lighttpd/pulp-redirect.lua.j2

@@ -66,6 +66,17 @@ function pulp_url(copr_path)
 
   local split = string_split(copr_path, "/")
 
+  -- Nobody should use devel repositories on user machines but in reality,
+  -- some people do. In such case we need to transform
+  -- @asahi/kernel/fedora-43-x86_64/devel/ into
+  -- @asahi/kernel/fedora-43-x86_64-devel/
+  -- This is not needed for devel repositories in Copr buildroots, because
+  -- copr-frontend does the same kind of transformation
+  if split[4] == "devel" then
+    split[3] = split[3] .. "-devel"
+    table.remove(split, 4)
+  end
+
   if copr_path:sub(-4) ~= ".rpm" then
     -- This is easy for .xml files inside the repodata, because in Pulp they are
     -- located at the same place where they would be on Copr backend.
@@ -74,14 +85,14 @@ function pulp_url(copr_path)
     -- This is the only thing that is needed to make `dnf copr enable` work, and
     -- for the repos to use the https://download.copr.fedorainfracloud.org CDN.
     -- This alone will not `dnf install` from the repos, though. See below.
-    url = url .. copr_path
+    url = url .. table.concat(split, "/")
 
   elseif split[4] == "Packages" then
     -- This is a .rpm file but the path already contains /Packages/, therefore
     -- we know that this is a `dnf install` situation. The repo already points
     -- to the correct path in Pulp, we just need to translate the CDN hostname
     -- to the Pulp hostname
-    url = url .. copr_path
+    url = url .. table.concat(split, "/")
 
   else
     -- This is a .rpm file but we are not accessing it through a repository.