docs: use exclude_pattern instead of :orphan:

Seems rst2man cannot handle :orphan:

docs/conf.py

@@ -81,7 +81,11 @@ language = None
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This patterns also effect to html_static_path and html_extra_path
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+exclude_patterns = [
+    '_build', 'Thumbs.db', '.DS_Store',
+    'proxmox-backup-client/man1.rst',
+    'pbs-copyright.rst',
+]
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.

docs/proxmox-backup-client/man1.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ==========================
 proxmox-backup-client
 ==========================