Honor connection_recycle_timeout in MysqlPersistenceDriver

The taskflow library allows us to customize idle_timeout. This change
makes the option set according to the equivalent option in oslo.db
similarly to the other options such as max_overflow.

Change-Id: I1c50f232c4f0c5c10a3dd5a928466f7ef67a9763

octavia/controller/worker/v2/taskflow_jobboard_driver.py

@@ -41,6 +41,7 @@ class MysqlPersistenceDriver(object):
             'max_pool_size': CONF.database.max_pool_size,
             'max_overflow': CONF.database.max_overflow,
             'pool_timeout': CONF.database.pool_timeout,
+            'idle_timeout': CONF.database.connection_recycle_time
         }
 
     def initialize(self):

releasenotes/notes/mysql-persistence-driver-idle_timeout-23a481d304c3d283.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Now the ``[database] connection_recycle_time`` option is also used by
+    connections in MySQL persistence driver.