Show the original string also when the translation is empty.

Currently the original (English) string is used when a particular
translation is not found. However, when a language file is updated or
generated by the make_language.rb script all strings are empty strings.
This patch facilitates running with a partially translated language file
without worrying about disappearing text.

Signed-off-by: Frédéric de Villamil <frederic@de-villamil.com>

vendor/plugins/localization/lib/localization.rb

@@ -5,7 +5,7 @@ module Localization
   @@lang = :default
 
   def self._(string_to_localize, *args)
-    translated = @@l10s[@@lang][string_to_localize] || string_to_localize
+    translated = @@l10s[@@lang][string_to_localize] ? string_to_localize : @@l10s[@@lang][string_to_localize]
     return translated.call(*args).to_s  if translated.is_a? Proc
     if translated.is_a? Array
       translated = if translated.size == 3 
@@ -18,7 +18,7 @@ def self._(string_to_localize, *args)
   end
 
   def self.__(string_to_localize, *args)
-    translated = @@l10s[@@lang][string_to_localize] || string_to_localize
+    translated = @@l10s[@@lang][string_to_localize] ? string_to_localize : @@l10s[@@lang][string_to_localize]
     return translated.call(*args).to_s  if translated.is_a? Proc
     if translated.is_a? Array
       translated = if translated.size == 3