Fixed an interesting bug. The following line does not do what many wo…

…uld expect: (#26)

lib/hiera/backend/vault_backend.rb

@@ -28,10 +28,10 @@ def initialize()
         begin
           @vault = Vault::Client.new
           @vault.configure do |config|
-            config.address = @config[:addr] if @config[:addr]
-            config.token = @config[:token] if @config[:token]
-            config.ssl_pem_file = @config[:ssl_pem_file] if @config[:ssl_pem_file]
-            config.ssl_verify = @config[:ssl_verify] if @config[:ssl_verify]
+            config.address = @config[:addr] unless @config[:addr].nil?
+            config.token = @config[:token] unless @config[:token].nil?
+            config.ssl_pem_file = @config[:ssl_pem_file] unless @config[:ssl_pem_file].nil?
+            config.ssl_verify = @config[:ssl_verify] unless @config[:ssl_verify].nil?
             config.ssl_ca_cert = @config[:ssl_ca_cert] if config.respond_to? :ssl_ca_cert
             config.ssl_ca_path = @config[:ssl_ca_path] if config.respond_to? :ssl_ca_path
             config.ssl_ciphers = @config[:ssl_ciphers] if config.respond_to? :ssl_ciphers