docker: do not use auth for cloudron namespace

src/docker.js

@@ -89,6 +89,9 @@ async function ping() {
 }
 
 async function getAuthConfig(image) {
+    // images in our cloudron namespace are always unauthenticated to not interfere with any user limits
+    if (image.startsWith('cloudron/')) return null;
+
     // https://github.com/docker/distribution/blob/release/2.7/reference/normalize.go#L62
     const parts = image.split('/');
     if (parts.length === 1 || (parts[0].match(/[.:]/) === null)) return null; // public docker registry