Remove archive_groupchats warning

[leszke]

The warning has been removed altogether with its mention in documentation.

[mongoose-im]

9042.1 / Erlang 23.0.3 / small_tests / 23029d1
Reports root / small

---

9042.2 / Erlang 23.0.3 / internal_mnesia / 23029d1
Reports root/ big
OK: 1502 / Failed: 0 / User-skipped: 161 / Auto-skipped: 0

---

9042.3 / Erlang 23.0.3 / odbc_mssql_mnesia / 23029d1
Reports root/ big
OK: 2770 / Failed: 0 / User-skipped: 229 / Auto-skipped: 0

---

9042.4 / Erlang 23.0.3 / mysql_redis / 23029d1
Reports root/ big
OK: 2765 / Failed: 0 / User-skipped: 234 / Auto-skipped: 0

---

9042.7 / Erlang 23.0.3 / elasticsearch_and_cassandra_mnesia / 23029d1
Reports root/ big
OK: 331 / Failed: 0 / User-skipped: 38 / Auto-skipped: 0

---

9042.5 / Erlang 23.0.3 / riak_mnesia / 23029d1
Reports root/ big
OK: 1628 / Failed: 0 / User-skipped: 181 / Auto-skipped: 0

---

9042.6 / Erlang 23.0.3 / ldap_mnesia / 23029d1
Reports root/ big
OK: 1404 / Failed: 0 / User-skipped: 259 / Auto-skipped: 0

---

9042.9 / Erlang 22.3 / pgsql_mnesia / 23029d1
Reports root/ big / small
OK: 2783 / Failed: 0 / User-skipped: 216 / Auto-skipped: 0

[codecov]

Codecov Report

Merging #3016 (0b6a2ca) into master (b532122) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3016      +/-   ##
==========================================
+ Coverage   78.53%   78.56%   +0.02%     
==========================================
  Files         376      376              
  Lines       31490    31488       -2     
==========================================
+ Hits        24730    24737       +7     
+ Misses       6760     6751       -9     

Impacted Files	Coverage Δ
src/mam/mod_mam.erl	89.25% <ø> (+0.36%)	⬆️
src/ejabberd_local.erl	71.64% <0.00%> (-1.50%)	⬇️
src/mod_bosh_socket.erl	77.63% <0.00%> (-1.25%)	⬇️
src/mod_muc_log.erl	77.72% <0.00%> (ø)
src/ejabberd_sm.erl	76.68% <0.00%> (+0.61%)	⬆️
src/ejabberd_s2s_out.erl	59.72% <0.00%> (+1.83%)	⬆️
src/cassandra/mongoose_cassandra_worker.erl	75.00% <0.00%> (+1.88%)	⬆️

---

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[janciesla8818]

All good. Thanks for the changes.