Investigate random segmentation faults with mod_proxy_balancer

[jajik]

Occasionally, there's a test failure due to a segmentation fault in mod_proxy_balancer tests. Find and fix the bug.

[jajik]

This is the corresponding log, I think

/usr/local/apache2
total 56
drwxr-xr-x  1 root root  4096 Jun 18 06:40 modules
drwxr-xr-x 14 root root 12288 Jun 18 06:40 manual
drwxr-xr-x  4 root root  4096 Jun 18 06:40 man
drwxr-xr-x  2 root root  4096 Jun 18 06:40 build
drwxr-xr-x  2 root root  4096 Jun 18 06:40 include
drwxr-xr-x  2 root root  4096 Jun 18 06:39 cgi-bin
drwxr-xr-x  2 root root  4096 Jun 18 06:39 logs
drwxr-xr-x  3 root root  4096 Jun 18 06:39 icons
drwxr-xr-x  3 root root  4096 Jun 18 06:39 error
drwxr-xr-x  2 root root  4096 Jun 18 06:39 htdocs
drwxr-xr-x  4 root root  4096 Jun 18 06:39 conf
drwxr-xr-x  2 root root  4096 Jun 18 06:39 bin
Starting httpd...
[Tue Jun 18 07:36:11.125108 2024] [manager:warn] [pid 13:tid 140686379596736] manager_init: can't find a ping/pong logic
[Tue Jun 18 07:36:11.126809 2024] [mpm_event:notice] [pid 13:tid 140686379596736] AH00489: Apache/2.4.59 (Unix) mod_cluster/2.0.0.Alpha1-SNAPSHOT configured -- resuming normal operations
[Tue Jun 18 07:36:11.126882 2024] [core:notice] [pid 13:tid 140686379596736] AH00094: Command line: '/usr/local/apache2/bin/httpd'