Remove unused macro definitions detected by rebar3_hank

?OFFLINE_TABLE_LOCK_THRESHOLD is unused:
  definition and usage added in 4103f30812
  definition copied, and usage moved to mod_offline_mnesia, in 901d2e0aed
  definition and usage removed in mod_offline_mnesia in d88e4d495f
  this definition looks useless
?VERSION_MULTICAST is unused:
  added in 0cf8d1fa6e
  it was never used
?DISCO_QUERY_TIMEOUT is unused:
  added in 0cf8d1fa6e
  it was never used
?FEATURE/1 is unused:
  added in 0cf8d1fa6e
  usage removed in bc33a3873d
?DEFAULT_MAX_USERS_PRESENCE is unused:
  added in f817762cc4
  usage removed in ba2b650464
?CT_XML is unused:
  added in 46568fb959
  removed in 3dc55c6d47

src/mod_muc_room.erl

@@ -78,8 +78,6 @@
 -define(MAX_USERS_DEFAULT_LIST,
 	[5, 10, 20, 30, 50, 100, 200, 500, 1000, 2000, 5000]).
 
--define(DEFAULT_MAX_USERS_PRESENCE,1000).
-
 -define(MUC_HAT_ADD_CMD, <<"http://prosody.im/protocol/hats#add">>).
 -define(MUC_HAT_REMOVE_CMD, <<"http://prosody.im/protocol/hats#remove">>).
 -define(MUC_HAT_LIST_CMD, <<"p1:hats#list">>).

src/mod_multicast.erl

@@ -66,8 +66,6 @@
 
 %% All the elements are of type value()
 
--define(VERSION_MULTICAST, <<"$Revision: 440 $ ">>).
-
 -define(PURGE_PROCNAME,
 	ejabberd_mod_multicast_purgeloop).
 
@@ -79,8 +77,6 @@
 
 -define(CACHE_PURGE_TIMER, 86400000).
 
--define(DISCO_QUERY_TIMEOUT, 10000).
-
 -define(DEFAULT_LIMIT_LOCAL_MESSAGE, 100).
 
 -define(DEFAULT_LIMIT_LOCAL_PRESENCE, 100).
@@ -268,8 +264,6 @@ process_iq(#iq{type = T}, _) when T == set; T == get ->
 process_iq(_, _) ->
     reply.
 
--define(FEATURE(Feat), Feat).
-
 iq_disco_info(From, Lang, State) ->
     Name = mod_multicast_opt:name(State#state.lserver),
     #disco_info{

src/mod_offline.erl

@@ -79,8 +79,6 @@
 
 -include("translate.hrl").
 
--define(OFFLINE_TABLE_LOCK_THRESHOLD, 1000).
-
 %% default value for the maximum number of user messages
 -define(MAX_USER_MESSAGES, infinity).