Merge pull request #569 from tansengming/dependabot/bundler/rack-2.2.6.4

Bump rack from 2.2.6.3 to 2.2.6.4

Author: tansengming

Gemfile.lock

@@ -231,7 +231,7 @@ GEM
     pundit (2.1.0)
       activesupport (>= 3.0.0)
     racc (1.6.2)
-    rack (2.2.6.3)
+    rack (2.2.6.4)
     rack-attack (6.3.1)
       rack (>= 1.0, < 3)
     rack-contrib (2.3.0)