Don't filter out contradictory nofailover tag (#2992)

* Ensure that nofailover will always be used if both nofailover and
failover_priority tags are provided
* Call _validate_failover_tags from reload_local_configuration() as well
* Properly check values in the _validate_failover_tags(): nofailover value should be casted to boolean like it is done when accessed in other places

features/steps/basic_replication.py

@@ -123,6 +123,6 @@ def check_patroni_log(context, message_list, level, node, timeout):
         messsages_of_level = context.pctl.read_patroni_log(node, level)
         if any(any(message in line for line in messsages_of_level) for message in message_list):
             break
-        time.sleep(1)
+        sleep(1)
     else:
         assert False, f"There were none of {message_list} {level} in the {node} patroni log after {timeout} seconds"