Hopefully apply new languages better, esp. during rehash

CHANGELOG.md

@@ -12,6 +12,7 @@ New release of Oragono!
 ### Security
 
 ### Added
+* Added new Turkish translation (thanks to [Yaser](https://crowdin.com/profile/Apsimati)!).
 * Added proposed IRCv3 capability [`draft/languages`](https://gist.github.com/DanielOaks/8126122f74b26012a3de37db80e4e0c6).
 * Added proposed IRCv3 capability [`draft/resume`](https://github.com/ircv3/ircv3-specifications/pull/306).
 * Added user modes, including:

irc/server.go

@@ -1299,6 +1299,13 @@ func (server *Server) applyConfig(config *Config, initial bool) error {
 		CapValues.Set(caps.Languages, newLanguageValue)
 	}
 
+	lm := NewLanguageManager(config.Languages.Default, config.Languages.Data)
+
+	server.logger.Debug("rehash", "Regenerating HELP indexes for new languages")
+	GenerateHelpIndices(lm)
+
+	server.languages = lm
+
 	// SASL
 	if config.Accounts.AuthenticationEnabled && !server.accountAuthenticationEnabled {
 		// enabling SASL