[Learning resource panel] If user choose a vocabulary name like ``(((()`` and exit panel without saving data it is not showing warning message.

[amir-qayyum-khan]

Use case:

• If users creates a vocabulary with name like (((().
• And Inside learning resource panel if he choose this vocabulary and then choose one of its terms.
• And try to close panel without saving data.

Expected behaviour:

• It should show a warning alert and ask user to save date.

Actual behaviour:

• Learning resource panel exit without any warning.
• On console found error:
  jquery.js:4224 Uncaught SyntaxError: Invalid regular expression: /(^|\.)select2\.(?:.*\.|)select2-term-()(((()(\.|$)/: Unterminated group
• It seems issue is with regular expression some where.

@pwilkins @pdpinch