Upgrade to rails 5.2.4.3 for some security fixes.

[CVE-2020-8162] Circumvention of file size limits in ActiveStorage
[CVE-2020-8164] Possible Strong Parameters Bypass in ActionPack
[CVE-2020-8165] Potentially unintended unmarshalling of user-provided objects in MemCacheStore and RedisCacheStore
[CVE-2020-8166] Ability to forge per-form CSRF tokens given a global CSRF token
[CVE-2020-8167] CSRF Vulnerability in rails-ujs

https://weblog.rubyonrails.org/2020/5/18/Rails-5-2-4-3-and-6-0-3-1-have-been-released/

Gemfile

@@ -64,7 +64,7 @@ gem "optimist",                       "~>3.0",         :require => false
 gem "pg",                                              :require => false
 gem "pg-dsn_parser",                  "~>0.1.0",       :require => false
 gem "query_relation",                 "~>0.1.0",       :require => false
-gem "rails",                          "~>5.2.4"
+gem "rails",                          "~>5.2.4", ">=5.2.4.3"
 gem "rails-i18n",                     "~>5.x"
 gem "rake",                           ">=12.3.3",      :require => false
 gem "rest-client",                    "~>2.0.0",       :require => false