gems: upgrade http-cookie to fix Rails 6.1 bug.

Upgrade the http-cookie gem to a personal fork containing a bugfix for a
http-cookie bug that is triggered by Rails 6.1.

The bug is that HTTP::Cookie objects raise an exception if they're
compared against non-cookie objects. This bug gets triggered when
the Nijie source strategy calls `Rails.cache.fetch` to cache the
Nijie login cookie. `Rails.cache.fetch` ends up calling
ActiveSupport::Cache::Store::Entry#dup_value!, which compares the cookie
with `true`, which triggers the exception.

The http-cookie gem hasn't been updated for 4 years, so we're stuck
patching the library ourselves.

Gemfile

@@ -41,6 +41,7 @@ gem 'scenic'
 gem 'ipaddress_2'
 gem 'http'
 gem 'activerecord-hierarchical_query'
+gem 'http-cookie', git: "https://github.com/danbooru/http-cookie"
 gem 'pundit'
 gem 'mail'
 gem 'nokogiri'

Gemfile.lock

@@ -1,3 +1,10 @@
+GIT
+  remote: https://github.com/danbooru/http-cookie
+  revision: 382d8a641e4df226e0e7b0d2bfaeadb2fe71dd84
+  specs:
+    http-cookie (1.0.4)
+      domain_name (~> 0.5)
+
 GIT
   remote: https://github.com/evazion/dtext_rb.git
   revision: a95bf1d537cbdba4585adb8e123f03f001f56fd7
@@ -161,8 +168,6 @@ GEM
       http-cookie (~> 1.0)
       http-form_data (~> 2.2)
       http-parser (~> 1.2.0)
-    http-cookie (1.0.3)
-      domain_name (~> 0.5)
     http-form_data (2.3.0)
     http-parser (1.2.2)
       ffi-compiler
@@ -405,6 +410,7 @@ DEPENDENCIES
   ffaker
   flamegraph
   http
+  http-cookie!
   ipaddress_2
   listen
   mail