storage: make listDir return paths relative to the root

this seems more natural to work with

src/test/storage-provider-test.js

@@ -122,7 +122,7 @@ describe('Storage', function () {
                 marker = result.marker;
             }
 
-            const expectedFiles = execSync(`find . -type f -printf '%P\n'`, { cwd: sourceDir, encoding: 'utf8' }).trim().split('\n');
+            const expectedFiles = execSync(`find . -type f -printf '%P\n'`, { cwd: sourceDir, encoding: 'utf8' }).trim().split('\n').map(p => `storage/${p}`);
             expect(allFiles.map(function (f) { return f.path; }).sort()).to.eql(expectedFiles.sort());
         });
 
@@ -189,7 +189,7 @@ describe('Storage', function () {
         const backupConfig = {
             provider: 's3',
             key: 'key',
-            prefix: 'unit.test',
+            prefix: 'prefix-test',
             bucket: 'cloudron-storage-test',
             accessKeyId: 'testkeyid',
             secretAccessKey: 'testsecret',
@@ -239,7 +239,7 @@ describe('Storage', function () {
             async copyObject(params) {
                 // CopySource already has the bucket path!
                 // Key already has prefix but no bucket ptah!
-                // console.log('Copying:', path.join(basePath, params.CopySource), path.join(bucketPathNoPrefix, params.Key));
+                console.log('Copying:', path.join(basePath, params.CopySource), path.join(bucketPathNoPrefix, params.Key));
                 await fs.promises.mkdir(path.dirname(path.join(bucketPathNoPrefix, params.Key)), { recursive: true });
                 await fs.promises.copyFile(path.join(basePath, params.CopySource.replace(/%2B/g, '+')), path.join(bucketPathNoPrefix, params.Key));
             }