Upper-case target language code "EN" is not recognized by tencent translate api, error code-2002

[wenchaoh]

I tried the plugin in omegaT. Error code is returned if the target language for project is set to "EN", and the same error code is returned twice if the target language is set to "EN-US". "EN" and "EN-US" are the default options in omegat project properties. However, Tencent uses lower-case letters to identify languages. The plugin works when I changed the target language manually to "en". Maybe the plugin can auto convert language code to lower case letters?

-2002 | 不支持的目标语言 (language not supported)

[Ovear]

稍微修了下。