Missing information in username validation error

Description

If the user enters a username of _aa on sign up, this fits the criteria as posed by the error but is not accepted by Zanata, as It does not start with a letter/number.
The error message given is "Between 3 and 20 letters, numbers and underscores only"

Environment

None

Status

Assignee

Unassigned

Reporter

Damian Jansen

Labels

None

Tested Version/s

None

Sprint

None

Fix versions

Affects versions

server-3.8.0

Priority

unspecified