Use mysql2 0.5.4

Gemfile

@@ -140,7 +140,7 @@ platforms :ruby, :mswin, :mswin64, :mingw, :x64_mingw do
 
   group :db do
     gem "pg", "~> 1.3"
-    gem "mysql2", "~> 0.5", github: "brianmario/mysql2"
+    gem "mysql2", "~> 0.5"
   end
 end
 

Gemfile.lock

@@ -1,9 +1,3 @@
-GIT
-  remote: https://github.com/brianmario/mysql2.git
-  revision: 25c42c712118b046eb9df7a0f50ffde1a04ee6d1
-  specs:
-    mysql2 (0.5.3)
-
 GIT
   remote: https://github.com/matthewd/websocket-client-simple.git
   revision: e161305f1a466b9398d86df3b1731b03362da91b
@@ -344,6 +338,7 @@ GEM
     mustache (1.1.1)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
+    mysql2 (0.5.4)
     net-http-persistent (4.0.1)
       connection_pool (~> 2.2)
     net-imap (0.2.2)
@@ -594,7 +589,7 @@ DEPENDENCIES
   minitest-bisect
   minitest-ci
   minitest-retry
-  mysql2 (~> 0.5)!
+  mysql2 (~> 0.5)
   nokogiri (>= 1.8.1, != 1.11.0)
   pg (~> 1.3)
   propshaft (>= 0.1.7)