Replicates CREATEMODE patch to the secondary auditlog file

At patch 45805be, @littlecho changed the behaviour to set the audit log
index/serial file permission. Before, it was using the default permission now
it is respecting the permission configured via SecAuditLogFileMode. This patch
replicates @littlecho's work to the secundary auditlog file.

apache2/apache2_config.c

@@ -1234,9 +1234,12 @@ static const char *cmd_audit_log2(cmd_parms *cmd, void *_dcfg, const char *p1)
         const char *file_name = ap_server_root_relative(cmd->pool, dcfg->auditlog2_name);
         apr_status_t rc;
 
+        if (dcfg->auditlog_fileperms == NOT_SET) {
+            dcfg->auditlog_fileperms = CREATEMODE;
+        }
         rc = apr_file_open(&dcfg->auditlog2_fd, file_name,
                 APR_WRITE | APR_APPEND | APR_CREATE | APR_BINARY,
-                CREATEMODE, cmd->pool);
+                dcfg->auditlog_fileperms, cmd->pool);
 
         if (rc != APR_SUCCESS) {
             return apr_psprintf(cmd->pool, "ModSecurity: Failed to open the secondary audit log file: %s",