Minor refactor

src/invidious.cr

@@ -390,7 +390,6 @@ get "/playlist" do |env|
   page = env.params.query["page"]?.try &.to_i?
   page ||= 1
 
-  if plid
   begin
     videos = extract_playlist(plid, page)
   rescue ex
@@ -398,9 +397,6 @@ get "/playlist" do |env|
     next templated "error"
   end
   playlist = fetch_playlist(plid)
-  else
-    next env.redirect "/"
-  end
 
   templated "playlist"
 end