Update the note about eetcd and dialyzer

now that the original issue has been resolved. We cannot bump gun just
yet, as eetcd is not yet compatible with gun 2.0.0

zhongwencool/eetcd#28
zhongwencool/eetcd#55
(cherry picked from commit 185e910)

Author: HoloRin

deps/rabbitmq_peer_discovery_etcd/BUILD.bazel

@@ -41,7 +41,8 @@ plt(
     name = "base_plt",
     plt = "//:base_plt",
     deps = DEPS + without(
-        # eetcd uses subdirectories in `src/`, and this confuses dialyzer.
+        # eetcd depends on gun, which still uses erlang:get_stacktrace/0
+        # and fails this rule if included
         "@eetcd//:erlang_app",
         RUNTIME_DEPS,
     ),