Core Rule Set: gitea's ordinary requests pass by default (closes #198)

The eighth change, internal/waf/gitea.conf, has some fields skip the
rules that refused ordinary gitea requests there, on gitea's paths only:
searches, file names and branch names. Referer skips 944130 too. A
registry's layer reuse skips 932260 on from, the seventh change.

The new setting SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE loads an operator's
own exclusions before the Core Rule Set's rules. The start stops, in
every mode, on a set file that cannot be read or does not parse, names
smallwebwaf's own ids, or holds a directive such as SecRuleRemoveById.

A test sends the recorded gitea requests at the defaults, none refused,
and three attacks, all refused.

Model: opus-5-5

internal/smallwebwaf/smallwebwaf.go

@@ -178,8 +178,7 @@ func RunServeWAF(ctx context.Context, params Params) int {
 
 	listener, err := (&net.ListenConfig{}).Listen(ctx, "tcp", cfg.ListenAddr)
 	if err != nil {
-		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR",
+		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR", "error", err.Error())
-			"error", err.Error())
 
 		return 1
 	}