mod_http_oauth2: Change password grant to take username instead of JID [BC] For consistency since the other grant types do not accept JIDs This has been like this from the beginning of this module. Changing this breaks backwards-compatibility with anything that relied on the JID as username, but things shouldn't really be using the password grant anyway as it is insecure.

This module blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```