Auto Import Session Token Amendment

[lowSoA]

Updated the "value" pattern in src/main/java/burp/ConfigParser.java#19 for session tokens which are longer than 256 characters.

In my current use case, the session token is 736 characters long, which will fail to populate the corresponding field when using the auto import feature. With the updated pattern, the session token is correctly parsed and added to the profile.

Addresses issue #17.