Fix 404 handling for endpoints matching short URLs

src/invidious.cr

@@ -2409,7 +2409,7 @@ get "/feed/subscriptions" do |env|
   env.set "user", user
 
   templated "subscriptions"
-  end
+end
 
 get "/feed/history" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
@@ -2434,7 +2434,7 @@ get "/feed/history" do |env|
   end
 
   templated "history"
-  end
+end
 
 get "/feed/channel/:ucid" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
@@ -2508,7 +2508,7 @@ get "/feed/channel/:ucid" do |env|
       end
     end
   end
-            end
+end
 
 get "/feed/private" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
@@ -5058,6 +5058,11 @@ error 404 do |env|
       response = client.get(response.headers["Location"])
     end
 
+    if response.body.empty?
+      env.response.headers["Location"] = "/"
+      halt env, status_code: 302
+    end
+
     html = XML.parse_html(response.body)
     ucid = html.xpath_node(%q(//meta[@itemprop="channelId"]))