Services: do not send the bot's nick in ChanServ commands

On Atheme, Anope, and oftc-ircservices, /cs unban, invite, op, and voice
implicitly assume the caller if no nick is given. However, certain combinations
such as /cs invite *with* a nick are not supported on atheme per
https://github.com/atheme/atheme/issues/568, and cause rejoin-on-kick to +i
channels to fail.

This fixes one part of GH-1118.

plugins/Services/plugin.py

@@ -405,7 +405,7 @@ class Services(callbacks.Plugin):
         chanserv = self.registryValue('ChanServ')
         if chanserv:
             msg = ircmsgs.privmsg(chanserv,
-                                  ' '.join([command, channel, irc.nick]))
+                                  ' '.join([command, channel]))
             irc.sendMsg(msg)
         else:
             if log: