Comment 2 for bug 1933226

Reviewed: https://review.opendev.org/c/openstack/watcher/+/797889
Committed: https://opendev.org/openstack/watcher/commit/9ca44fa3ab16ba99c65b75c7fa2fde3b2c160b1d
Submitter: "Zuul (22348)"
Branch: master

commit 9ca44fa3ab16ba99c65b75c7fa2fde3b2c160b1d
Author: ericxiett <eric_xiett@163.com>
Date: Thu Jun 24 12:27:05 2021 +0000

    Replace deprecated with_lockmode with with_for_update

    The Query.with_lockmode() method is deprecated since version 0.9.0
    and will be removed in a future release. [1]
    This patch replaces it with Query.with_for_update().
    The 'faultstring' was been modified to 'Exactly 5 or 6 columns has to be
    specified for iterator expression', so adds one space between "iterator"
    and "expression" for 'expected_error_msg'.

    Also use upper-constraints in doc build to avoid issues in pdf build.

    [1]
    https://docs.sqlalchemy.org/en/13/orm/query.html#sqlalchemy.orm.query.Query.with_lockmode

    Closes-Bug: #1933226
    Change-Id: I0ad514da647bb08790259fd27e56a41f6dbbbaa0