Add missing parenthesis to add_compiler plan

Author: timidri

plans/add_compiler.pp

@@ -83,7 +83,7 @@
   run_command('systemctl start puppet.service', peadm::flatten_compact([
     $primary_postgresql_target,
     $compiler_target,
-  ])
+  ]))
 
   return("Adding or replacing compiler ${$compiler_target.peadm::certname()} succeeded.")