refactor: remove Postal.database_url

lib/postal/config.rb

@@ -86,14 +86,6 @@ module Postal
     end
   end
 
-  def self.database_url
-    if config.main_db
-      "mysql2://#{CGI.escape(config.main_db.username.to_s)}:#{CGI.escape(config.main_db.password.to_s)}@#{config.main_db.host}:#{config.main_db.port}/#{config.main_db.database}?reconnect=true&encoding=#{config.main_db.encoding || 'utf8mb4'}&pool=#{config.main_db.pool_size}"
-    else
-      "mysql2://root@localhost/postal"
-    end
-  end
-
   def self.logger_for(name)
     @loggers ||= {}
     @loggers[name.to_sym] ||= begin

lib/postal/message_db/mysql.rb

@@ -7,7 +7,13 @@ module Postal
       # it would be undesirable as we'd just end up with lots of connections.
 
       def self.new_client
-        Mysql2::Client.new(host: Postal.config.message_db.host, username: Postal.config.message_db.username, password: Postal.config.message_db.password, port: Postal.config.message_db.port, reconnect: true, encoding: Postal.config.message_db.encoding || "utf8mb4")
+        Mysql2::Client.new(
+          host: Postal.config.message_db.host,
+          username: Postal.config.message_db.username,
+          password: Postal.config.message_db.password,
+          port: Postal.config.message_db.port,
+          encoding: Postal.config.message_db.encoding || "utf8mb4"
+        )
       end
 
       @free_clients = []