mod_sasl2_fast: Fix harmless off-by-one error (invalidates existing tokens!) Problem: This was causing the key to become "<token>--cur" instead of the expected "<token>-cur". As the same key was used by the code to both set and get, it still worked. Rationale for change: Although it worked, it's unintended, inconsistent and messy. It increases the chances of future bugs due to the unexpected format. Side-effects of change: Existing '--cur' entries will not be checked after this change, and therefore existing FAST clients will fail to authenticate until they attempt password auth and obtain a new FAST token. Existing '--cur' entries in storage will not be cleaned up by this commit, but this is considered a minor issue, and okay for the relatively few FAST deployments.

Contributing
============

Guidelines for developers
-------------------------

-   Each module should be contained in a folder of its name (e.g.\
     `mod_ping/mod_ping.lua`)
-   Each module should have a `README.markdown` page in their folder
    with a description, usage, configuration and todo sections (feel
    free to copy an existing one as a template)
-   Commit messages should begin with the name of the plugin they are
    for (e.g. `mod_ping: Set correct namespace on pongs`)

Instructions on cloning the repository are at
<https://prosody.im/doc/installing_modules#prosody-modules>