Change SQL charset for message_db to utf8mb4

lib/postal/message_db/mysql.rb

@@ -7,7 +7,7 @@ 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)
+        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')
       end
 
       @free_clients = []

lib/postal/message_db/provisioner.rb

@@ -33,7 +33,7 @@ module Postal
       # Creates a new empty database
       #
       def create
-        @database.query("CREATE DATABASE `#{@database.database_name}` CHARSET utf8 COLLATE UTF8_UNICODE_CI;")
+        @database.query("CREATE DATABASE `#{@database.database_name}` CHARSET utf8mb4 COLLATE utf8mb4_bin;")
         true
       rescue Mysql2::Error => e
         e.message =~ /database exists/ ? false : raise
@@ -185,7 +185,7 @@ module Postal
             s << ", PRIMARY KEY (`id`)"
           end
 
-          s << ") ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;"
+          s << ") ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4;"
         end
       end