update version code and update info

src/updates.rb

@@ -18,7 +18,7 @@ require 'net/http'
 require 'uri'
 
 # @type const RELEASE_SERIAL_CODE: String
-RELEASE_SERIAL_CODE = '60176fa'
+RELEASE_SERIAL_CODE = '83acd30'
 # @type const CHANNEL: String
 CHANNEL = 'master'
 # @type const VERSION_LIST_URL: String
@@ -42,7 +42,6 @@ class UpdateManager
     end
   rescue StandardError => e
     MethodExecutor.record('error', 'updates', "Failed to fetch version list: #{e}")
-    nil
   end
   # rubocop:enable Metrics/MethodLength
 
@@ -65,7 +64,8 @@ class UpdateManager
     end
 
     latest = lines.last
-    MethodExecutor.record('info', 'updates', "Newer version #{latest} available (current: #{RELEASE_SERIAL_CODE}).")
+    MethodExecutor.record('info', 'updates',
+                          "Newer version #{latest} available (current: #{RELEASE_SERIAL_CODE}), use git to update.")
     { type: :NewerAvailable, version: latest }
   end
   # rubocop:enable Metrics/MethodLength