[manual] puppet: Rename humbug=>zulip in nginx configuration filenames.

We need to manually remove the old humbug and humbug-staging sites-*
files when we deploy this via puppet.

(imported from commit d25e0172a14032c5acf1501668602d34b1b13b85)

servers/puppet/modules/zulip/manifests/prod_app_frontend.pp

@@ -1,17 +1,17 @@
 class zulip::prod_app_frontend {
   class { 'zulip::app_frontend': }
 
-  file { "/etc/nginx/sites-available/humbug":
+  file { "/etc/nginx/sites-available/zulip":
     require => Package[nginx],
     ensure => file,
     owner  => "root",
     group  => "root",
     mode => 644,
-    source => "puppet:///modules/zulip/nginx/sites-available/humbug",
+    source => "puppet:///modules/zulip/nginx/sites-available/zulip",
   }
-  file { '/etc/nginx/sites-enabled/humbug':
+  file { '/etc/nginx/sites-enabled/zulip':
     ensure => 'link',
-    target => '/etc/nginx/sites-available/humbug',
+    target => '/etc/nginx/sites-available/zulip',
   }
 
   file { [ "/srv/www/", "/srv/www/dist/", "/srv/www/dist/api",

servers/puppet/modules/zulip/manifests/staging_app_frontend.pp

@@ -4,17 +4,17 @@ class zulip::staging_app_frontend {
   $packages = [ "python-html2text" ]
   package { $packages: ensure => "installed" }
 
-  file { "/etc/nginx/sites-available/humbug-staging":
+  file { "/etc/nginx/sites-available/zulip-staging":
     require => Package[nginx],
     ensure => file,
     owner  => "root",
     group  => "root",
     mode => 644,
-    source => "puppet:///modules/zulip/nginx/sites-available/humbug-staging",
+    source => "puppet:///modules/zulip/nginx/sites-available/zulip-staging",
   }
-  file { '/etc/nginx/sites-enabled/humbug-staging':
+  file { '/etc/nginx/sites-enabled/zulip-staging':
     ensure => 'link',
-    target => '/etc/nginx/sites-available/humbug-staging',
+    target => '/etc/nginx/sites-available/zulip-staging',
   }
   file { "/etc/cron.d/email-mirror":
     ensure => file,