Once finished locking/unlocking, stop loading indicator

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

shell_integration/MacOSX/NextcloudIntegration/FileProviderUIExt/Locking/LockViewController.swift

@@ -185,6 +185,7 @@ class LockViewController: NSViewController {
             }
             if error == .success {
                 descriptionLabel.stringValue = "File \(self.locking ? "locked" : "unlocked")!"
+                stopIndicatingLoading()
             } else {
                 presentError("Could not lock file: \(error.errorDescription).")
             }