Move the logging for sync_config out of the sync_config method

This was a problem for the EventCatcher when sync_config was called
as a part of worker initialization. The EventCatcher uses its ems
hostname as a part of its log prefix, but the ems isn't set up until
after the first call to sync_config.

This was leading to errors when the worker was starting:
[----] I, [2019-12-19T17:51:48.407958 ManageIQ#11054:2ab1a6d9a5f8]  INFO -- : Starting ManageIQ::Providers::Vmware::InfraManager::EventCatcher with runner options {:ems_id=>"2", :guid=>"43a315ba-39ff-4326-99a6-89b3af48b1ee"}
[----] I, [2019-12-19T17:51:48.451836 ManageIQ#11054:2ab1a6d9a5f8]  INFO -- : Deleting worker record for ManageIQ::Providers::Vmware::InfraManager::EventCatcher, id 310
/home/ncarboni/Source/manageiq/app/models/manageiq/providers/base_manager/event_catcher/runner.rb:63:in `log_prefix': undefined method `hostname' for nil:NilClass (NoMethodError)
        from /home/ncarboni/Source/manageiq/app/models/miq_worker/runner.rb:242:in `sync_config'
        from /home/ncarboni/Source/manageiq/app/models/miq_worker/runner.rb:52:in `worker_initialization'
        from /home/ncarboni/Source/manageiq/app/models/miq_worker/runner.rb:42:in `initialize'
        from /home/ncarboni/Source/manageiq/lib/workers/bin/run_single_worker.rb:113:in `new'
        from /home/ncarboni/Source/manageiq/lib/workers/bin/run_single_worker.rb:113:in `<main>'

app/models/miq_worker/runner.rb

@@ -239,7 +239,6 @@ def do_exit(message = nil, exit_code = 0)
   end
 
   def sync_config
-    _log.info("#{log_prefix} Synchronizing configuration...")
     # Sync roles
     @active_roles = MiqServer.my_active_roles(true)
     after_sync_active_roles
@@ -258,7 +257,6 @@ def sync_config
     $log.log_hashes(@cfg)
 
     @worker.release_db_connection if @worker.respond_to?(:release_db_connection)
-    _log.info("#{log_prefix} Synchronizing configuration complete...")
   end
 
   def sync_log_level
@@ -324,7 +322,12 @@ def heartbeat
 
     heartbeat_to_file
 
-    sync_config                  if config_out_of_date?
+    if config_out_of_date?
+      _log.info("#{log_prefix} Synchronizing configuration...")
+      sync_config
+      _log.info("#{log_prefix} Synchronizing configuration complete...")
+    end
+
     process_messages_from_server unless MiqEnvironment::Command.is_podified?
 
     @last_hb = now