Fix varchar size

[stonebuzz]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes error at create a block #1046

Prevent MySQL error

MySQL query error: Data too long for column 'language' at row 1 (1406) in SQL query "INSERT INTO glpi_plugin_fields_labeltranslations (itemtype, items_id, language, label) VALUES ('PluginFieldsContainer', '14', 'es_419', 'test')".

Screenshots (if appropriate):