fix(admin): underline too short

Signed-off-by: John Molakvoæ <skjnldsv@users.noreply.github.com>

Author: skjnldsv

admin_manual/configuration_files/encryption_configuration.rst

@@ -338,7 +338,7 @@ Troubleshooting
 ---------------
 
 Why don't I see the recovery key option in the Encryption settings?
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Recovery keys are only available in per-user key mode. Since Nextcloud 13, the default
 encryption mode uses master keys (system-wide encryption). Master key mode does not expose