CaseInsensitiveUsername is enabled by default in toml configurations

[rksk]

Until IS 5.8.0, the default value for CaseInsensitiveUsername was false (if not specified in user-mgt.xml). But with the new configuration model, it has been set to true (in default.json).

Enabling this could lead to performance degradation when searching for users as the number of users increases if proper indexing has not been done. Therefore this needs to be mentioned in the changelog.

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If you are migrating from an older version (<=5.8.0) of WSO2 IS and if you had not set a value for CaseInsensitiveUsername in the user-mgt.xml, it is required to set the following in the deployment.toml in order to preserve the previous behavior.

[user_store]
properties.CaseInsensitiveUsername = false

OR

[user_store.properties]
CaseInsensitiveUsername = false

Additionally, UseCaseSensitiveUsernameForCacheKeys also has to be false in order to avoid cache-related inconsistencies with MySQL and MSSQL DBs.

[1] https://docs.wso2.com/display/IS580/Configuring+a+JDBC+User+Store