Get an error when running 'openstack undercloud upgrade'

Issue

• The following error occurs when upgrading from RHOSP 16.2 to RHOSP 17.1

++ cat /run_command\
+ CMD='/usr/bin/bootstrap_host_exec neutron_api neutron-db-manage upgrade heads'\
+ ARGS=\
+ [[ ! -n '' ]]\
+ . kolla_extend_start\
+ echo 'Running command: '\\\\''/usr/bin/bootstrap_host_exec neutron_api neutron-db-manage upgrade heads'\\\\'''\
+ umask 0022\
+ exec /usr/bin/bootstrap_host_exec neutron_api neutron-db-manage upgrade heads\
INFO  [alembic.runtime.migration] Context impl MySQLImpl.\
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.\
INFO  [alembic.runtime.migration] Context impl MySQLImpl.\
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.\
INFO  [alembic.runtime.migration] Running upgrade 86274d77933e -> f4b9654dd40c\
  :
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (1050, \\\"Table 'ovn_revision_numbers' already exists\\\")\
[SQL: \
CREATE TABLE ovn_revision_numbers (\
\\tstandard_attr_id BIGINT, \
\\tresource_uuid VARCHAR(36) NOT NULL, \
\\tresource_type VARCHAR(36) NOT NULL, \
\\trevision_number BIGINT NOT NULL DEFAULT '0', \
\\tcreated_at DATETIME NOT NULL, \
\\tupdated_at TIMESTAMP NULL, \
\\tPRIMARY KEY (resource_uuid, resource_type), \
\\tFOREIGN KEY(standard_attr_id) REFERENCES standardattributes (id) ON DELETE SET NULL\
)ENGINE=InnoDB\
\
]\