opendkim: use opendkim as selector as before

Author: missytake

cmdeploy/src/cmdeploy/opendkim/deployer.py

@@ -23,7 +23,7 @@ def install(self):
 
     def configure(self):
         domain = self.mail_domain
-        dkim_selector = "dkim"
+        dkim_selector = "opendkim"
         """Configures OpenDKIM"""
         need_restart = False