Set logger webhook proxy on subnet proxy change (#16665)

Signed-off-by: Shubhendu Ram Tripathi <shubhendu@minio.io>

internal/config/subnet/subnet.go

@@ -32,6 +32,9 @@ import (
 
 const (
 	respBodyLimit = 1 << 20 // 1 MiB
+
+	// LoggerWebhookName - subnet logger webhook target
+	LoggerWebhookName = "subnet"
 )
 
 // Upload given file content (payload) to specified URL