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.

# Introduction

This module implements [XEP-xxxx: Room Activity Indicators](https://xmpp.org/extensions/inbox/room-activity-indicators.html).

## Requirements

This module currently depends on mod_muc_markers, so review the requirements for that module.

# Configuring

## Enabling

``` {.lua}
Component "rooms.example.net" "muc"
modules_enabled = {
    "muc_rai";
    "muc_markers";
    "muc_mam";
}
```

## Settings

|Name |Description |Default |
|-----|------------|--------|
|muc_rai_max_subscribers| Maximum number of active subscriptions allowed | 1024 |

# Compatibility

Requires Prosody trunk (2020-04-15+).