update bw to 4.3, add .provides() to metadata reactors

bundles/postfix/metadata.py

@@ -46,7 +46,9 @@ else:
 
 
 # FIXME find a working, non-shitty check for that
-#@metadata_reactor
+#@metadata_reactor.provides(
+#    'icinga2_api/postfix/services',
+#)
 def fill_icinga_spam_blocklist_check_with_hostname(metadata):
     checks = {}
 
@@ -67,7 +69,10 @@ def fill_icinga_spam_blocklist_check_with_hostname(metadata):
     }
 
 
-@metadata_reactor
+@metadata_reactor.provides(
+    'letsencrypt/domains',
+    'letsencrypt/reload_after',
+)
 def letsencrypt(metadata):
     if not node.has_bundle('letsencrypt'):
         raise DoNotRunAgain