설치화면에서 언어 선택이 잘못 나타나는 문제 해결. firebird description 추가

git-svn-id: http://xe-core.googlecode.com/svn/sandbox@4195 201d5d3c-b55e-5fd7-737f-ddc643e51545

modules/install/lang/en.lang.php

@@ -146,6 +146,7 @@ EndOfLicense;
         'sqlite3_pdo' => 'Suppots sqlite3 by PHP\'s PDO.<br />When installing, DB file should be created at unreachable place from web.',
         'cubrid' => 'Use CUBRID DB.',
         'postgresql' => 'Use PostgreSql DB.',
+        'firebird' => 'Use firebird DB.',
     );
 
     $lang->form_title = 'Please input DB &amp; Admin information';