Source: Remove reduntant save() call

Source::clear_etags does a save already, so it's not needed to call
it twice.

podcasts-data/src/models/source.rs

@@ -175,7 +175,6 @@ impl Source {
             debug!("Previous Source: {:#?}", &self);
 
             self.set_uri(url.to_string());
-            self = self.save()?;
             self = self.clear_etags()?;
 
             debug!("Updated Source: {:#?}", &self);