unrealircd: Update to 5.0.4

UnrealIRCd 5.0.4 Release Notes
===============================

This new 5.0.4 version fixes quite a number of bugs. It contains only two small feature improvements.

Fixes:
* When placing a SHUN on an online user it was not always effective.
* Channeldb was not properly restoring all channel modes, such as +P.
* When upgrading UnrealIRCd it could sometimes crash the currently
  running IRC server (rare), or trigger a crash report on
  ```./unrealircd restart``` (quite common).
* UnrealIRCd was giving up too easily on ident lookups.
* Crash when unloading a module with moddata.
* Crash if an authenticated server sends wrong information (rare).
* Removing a TEMPSHUN did not work if the user was on another server.
* SAJOIN to 0 (part all channels) resulted in a desync when used on remote users.
* Forced nick change from services was not showing up if the user
  was not in any channels.

Enhancements:
* New option [set::hide-idle-time::policy](https://www.unrealircd.org/docs/Set_block#set%3A%3Ahide-idle-time)
  by which you can change usermode +I (hide idle time in WHOIS) from
  oper-only to settable by users. More options will follow in a future
  release.
* In WHOIS you can now see if a user is currently (temp)shunned.
  This only works for locally connected users for technical reasons,
  so use ```/WHOIS Nick Nick``` to see it for remote users.

Changes:
* The oper notices and logging with regards to server linking have changed
  a little. They are more consistent and log more now.
* When an IRCOp tries to oper up from an insecure connection we will now
  mention the https://www.unrealircd.org/docs/FAQ#oper-requires-tls page.
  This message is customizable through
  [set::plaintext-policy::oper-message](https://www.unrealircd.org/docs/Set_block#set::plaintext-policy).
* The French HELPOP text was updated.

(nia)