Prevent exchange logging crash

Don't let the `log` callback of exchange_logging handler crash,
because in case of a crash OTP logger removes the exchange_logger
handler, which in turn deletes the log exchange and its bindings.

It was seen several times in production that the log exchange suddenly
disappears and without debug logging there is no trace of why.

With this commit `erlang:display` will print the reason and stacktrace
to stderr without using the logging infrastructure.

Author: gomoripeti

deps/rabbit/src/rabbit_logger_exchange_h.erl

@@ -44,8 +44,18 @@ log(#{meta := #{mfa := {?MODULE, _, _}}}, _) ->
     ok;
 log(LogEvent, Config) ->
     case rabbit_boot_state:get() of
-        ready -> do_log(LogEvent, Config);
-        _     -> ok
+        ready ->
+            try
+                do_log(LogEvent, Config)
+            catch
+                C:R:S ->
+                    %% don't let logging crash, because then OTP logger
+                    %% removes the logger_exchange handler, which in
+                    %% turn deletes the log exchange and its bindings
+                    erlang:display({?MODULE, crashed, {C, R, S}})
+            end,
+            ok;
+        _ -> ok
     end.
 
 do_log(LogEvent, #{config := #{exchange := Exchange}} = Config) ->