doc/_ext: do not import unused module

PyField and BuildEnvironment are not used in `ceph_confval.py`, so
let's remove the corresponding import statements.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/doc/_ext/ceph_confval.py b/doc/_ext/ceph_confval.py
index da93d1b415c4e5ded571d275dc8f5bf0ec263537..3a1a9b8abeafdd73fc7327a19e49cdcdf3ed51af 100644 (file)
--- a/doc/_ext/ceph_confval.py
+++ b/doc/_ext/ceph_confval.py
@@ -10,8 +10,6 @@ from docutils.statemachine import StringList
 
 from sphinx import addnodes
 from sphinx.directives import ObjectDescription
-from sphinx.domains.python import PyField
-from sphinx.environment import BuildEnvironment
 from sphinx.locale import _
 from sphinx.util import logging, status_iterator, ws_re
 from sphinx.util.docutils import switch_source_input, SphinxDirective