Fix Bind failed when bind config changed everytime

The current file_file to configure dns config file exist a bug:
it will change the dns confif file every time when run puppet, then
bind will fail to resolve any records.

manifests/dns.pp

@@ -28,7 +28,8 @@ class designate::dns (
 
   file_line {'dns designate path':
     path    => $dns::params::namedconf_path,
-    line    => "include \"${designatefile}\";",
+    line    => "include  \"${designatefile}\";",
+    match   => '^include  \"(.*)$',
     require => Class['designate'],
   }