increase robustness of vault creation:

* clean up after failed vault creation
* ignore if storage readme cannot be created

src/main/java/org/cryptomator/ui/addvaultwizard/CreateNewVaultPasswordController.java

@@ -44,8 +44,10 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.security.SecureRandom;
+import java.util.Comparator;
 import java.util.ResourceBundle;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import static java.nio.charset.StandardCharsets.US_ASCII;
 import static org.cryptomator.common.Constants.MASTERKEY_FILENAME;
@@ -195,12 +197,28 @@ public class CreateNewVaultPasswordController implements FxController {
 			} catch (CryptoException e) {
 				throw new IOException("Failed initialize vault.", e);
 			}
+		} finally {
+			AtomicBoolean cleanupFailed = new AtomicBoolean(false);
+			Files.walk(path)
+				.sorted(Comparator.reverseOrder())
+				.forEach(p -> {
+					try {
+						Files.deleteIfExists(p);
+					} catch (IOException e) {
+						cleanupFailed.set(false);
+					}
+				});
+			if(cleanupFailed.get()) {
+				LOG.warn("Failed to cleanup after failed vault creation at {}. Leftovers need to be deleted manually.", path);
+			}
 		}
 
 		// 4. write vault-external readme file:
 		String storagePathReadmeFileName = resourceBundle.getString("addvault.new.readme.storageLocation.fileName");
 		try (WritableByteChannel ch = Files.newByteChannel(path.resolve(storagePathReadmeFileName), StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE)) {
 			ch.write(US_ASCII.encode(readmeGenerator.createVaultStorageLocationReadmeRtf()));
+		} catch (IOException e) {
+			LOG.warn("Unable to create vault storage location readme.", e);
 		}
 
 		LOG.info("Created vault at {}", path);