Fix review comments and new changes in config (#8515)

- Migrate and save only settings which are enabled
- Rename logger_http to logger_webhook and
  logger_http_audit to audit_webhook
- No more pretty printing comments, comment
  is a key=value pair now.
- Avoid quotes on values which do not have space in them
- `state="on"` is implicit for all SetConfigKV unless
  specified explicitly as `state="off"`
- Disabled IAM users should be disabled always

cmd/config/identity/ldap/config.go

@@ -115,6 +115,9 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
 	}
 	stateBool, err := config.ParseBool(env.Get(EnvLDAPState, kvs.Get(config.State)))
 	if err != nil {
+		if kvs.Empty() {
+			return l, nil
+		}
 		return l, err
 	}
 	ldapServer := env.Get(EnvServerAddr, kvs.Get(ServerAddr))

cmd/config/identity/ldap/legacy.go

@@ -20,13 +20,12 @@ import "github.com/minio/minio/cmd/config"
 
 // SetIdentityLDAP - One time migration code needed, for migrating from older config to new for LDAPConfig.
 func SetIdentityLDAP(s config.Config, ldapArgs Config) {
+	if !ldapArgs.Enabled {
+		// ldap not enabled no need to preserve it in new settings.
+		return
+	}
 	s[config.IdentityLDAPSubSys][config.Default] = config.KVS{
-		config.State: func() string {
-			if !ldapArgs.Enabled {
-				return config.StateOff
-			}
-			return config.StateOn
-		}(),
+		config.State:       config.StateOn,
 		config.Comment:     "Settings for LDAP, after migrating config",
 		ServerAddr:         ldapArgs.ServerAddr,
 		STSExpiry:          ldapArgs.STSExpiryDuration,