Serve EPUBs instead XTC in daily OPDS

It turns out it is currently impossible for the Xteink X4 to download
XTC files from an OPDS server. So I switched the built-in OPDS server in
this binary (daily.hallada.net/opds) to serve the EPUB files instead of
the XTC files. The X4 is pretty capable of reading the X4 edition of the
EPUB that was optimized for it anyways, and I prefer the flexibility of
EPUB, so I might end up eventually deleting the XTC conversion. For now,
I kept the conversion step (in case I ever want to ever try manually
copying them to the device) and I keep a limited number of XTC issues on
the server since they are quite big in filesize. The BookOrbit
integration is now optional since the built-in OPDS server is able to
serve the EPUBs. In my installation, I serve the EPUBs through both. The
daily.hallada.net/opds server is just a little quicker to navigate and
download the EPUBs on the X4 since the BookOrbit OPDS requires diving
into a couple layers of folders before you get to the files.

src/pipeline.rs

@@ -510,7 +510,7 @@ async fn run_stages(
         );
         None
     } else {
-        let published = publish::publish_issue(db, config, &issue, &artifacts, xtc.as_deref())
+        let published = publish::publish_issue(config, &issue, &artifacts, xtc.as_deref())
             .await
             .context("publishing the issue")?;
         record_issue(db, &issue, &published)