If the rpc in `emqx_dashboard_monitor_api:get_collect/1` fails, an
empty map is return. But the current function expects a 4-tuple,
which results in a 500 error returned on such occasions.
```
curl -su admin:public localhost:8888/api/v5/monitor/current | jq .
{
"code": "INTERNAL_ERROR",
"message": "error, function_clause, [{emqx_dashboard_monitor_api,format_current_metrics,[[#{},{0,0,0,0},{0,0,0,0}],{0,0,0,0}],[{file,\"emqx_dashboard_monitor_api.erl\"},{line,179}]},{emqx_dashboard_monitor_api,current_counters,2,[{file,\"emqx_dashboard_monitor_api.erl\"},{line,167}]},{minirest_handler,apply_callback,3,[{file,\"minirest_handler.erl\"},{line,112}]},{minirest_handler,init,2,[{file,\"minirest_handler.erl\"},{line,38}]},{cowboy_handler,execute,2,[{file,\"cowboy_handler.erl\"},{line,41}]},{cowboy_stream_h,execute,3,[{file,\"cowboy_stream_h.erl\"},{line,318}]},{cowboy_stream_h,request_process,3,[{file,\"cowboy_stream_h.erl\"},{line,302}]},{proc_lib,init_p_do_apply,3,[{file,\"proc_lib.erl\"},{line,226}]}]"
}
```
If an empty username or password are given during the initialization
of `emqx_dashboard_admin`, it'll return just the atom `ok`, which
breaks the expected `{ok, _}` in `emqx_dashboard_app:start/2`.
```
{'EXIT',
{{failed_to_start_app,emqx_dashboard,
{emqx_dashboard,
{bad_return,
{{emqx_dashboard_app,start,[normal,[]]},
{'EXIT',
{{badmatch,ok},
[{emqx_dashboard_app,start,2,
[{file,
"/home/thales/dev/emqx/emqx/apps/emqx_dashboard/src/emqx_dashboard_app.erl"},
{line,32}]},
{application_master,start_it_old,4,
[{file,"application_master.erl"},{line,293}]}]}}}}}}}}
```
* fix: ./bin/emqx ping return pong
* chore: waiting longer for logger flush log to disk
* fix: change swagger page's limit from 100 to 1000
* chore: type wrong
* fix: sync log to disk by logger_disk_log_h:filesync
The compile flag was introduced in EQM X 4.3 series
where CE and EE code was diverged large enough which made
non-practicle to determin edition at runtime.
such approach made testing quite challenging as we'll have to
build with different compile flags inorder to run per-edition
test cases
In this commit, we try to retrieve edition info from EMQX's
description text, (put to PT for fast access) at runtime
so we can test ALL editions from a super-set edition (EE).
