!!!! WARNING !!!!
     mod_log_config and mod_log_config-st are conflicting.

In order to use correctly mod_log_config-st, you have to replace:
LoadModule log_config_module  libexec/apache2/mod_log_config.so
by
LoadModule log_config_module  libexec/apache2/mod_log_config-st.so
in your httpd.conf.