[FIX] Table renamed crm_lead_lost_reason using rename_tables (#1525)

This fixes renaming crm_lead_lost_reason to crm_lost_reason using
openupgrade's rename_tables so that sequences are renamed as well.
Since the table is created in an OCA module, first it is checked that
the table exists

addons/crm/migrations/9.0.1.0/pre-migration.py

@@ -94,6 +94,5 @@ def migrate(env, version):
         [('4', '3')], table='crm_lead',
     )
     cr.execute("update crm_lead set type='opportunity' where type is null")
-    # Needed for crm_lead_lost_reason migration
-    cr.execute("ALTER TABLE IF EXISTS crm_lead_lost_reason "
-               "RENAME TO crm_lost_reason")
+    if openupgrade.table_exists(cr, 'crm_lead_lost_reason'):
+        openupgrade.rename_tables(cr, [('crm_lead_lost_reason', 'crm_lost_reason')])