Toggle `nginx` setup behavior.

cookbooks/nginx/default.rb

@@ -33,10 +33,14 @@ end
 end
 
 # Prerequisites for Building nginx:
+if node['nginx']['skip_webadm']
   include_recipe './webadm.rb'
+end
 
 # Install Let's Encrypt:
+if node['nginx']['skip_lego']
   include_recipe './lego.rb'
+end
 
 # Build nginx:
 include_recipe './build.rb'