Fixes https://emqx.atlassian.net/browse/EMQX-10944
Also updates ekka -> 0.15.15, mria -> 0.6.4
How to test
===========
1. Start 2 or more EMQX nodes and merge them in a cluster.
2. Stop them in order.
3. Start only the first node that was stopped in the previous step.
4. Wait until the log is printed.
Or, more easily:
1. Start 2 or more EMQX nodes and merge them in a cluster.
2. Stop all but one.
3. Run `mria_mnesia:diagnosis([]).` on that node.
Example output
==============
```
Check check_open_ports should get ok but got #{msg =>
"some ports are unreachable",
results =>
#{'emqx@172.100.239.4' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
4}],
status =>
bad_ports},
'emqx@172.100.239.5' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
5}],
status =>
bad_ports}}}
```
After one node is back:
```
Check check_open_ports should get ok but got #{msg =>
"some ports are unreachable",
results =>
#{'emqx@172.100.239.4' =>
#{ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
4}],
status => ok},
'emqx@172.100.239.5' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
5}],
status =>
bad_ports}}}
```
d6935b6a67