Level command on user without avatarUrl result in index out of bound in go

[ArmandBriere]

Is your feature request related to a problem? Please describe.
!level @userwithoutavatar -> This is broken

Describe the solution you'd like
The level.go file is the problem on the regex

re := regexp.MustCompile("avatars/(.*).png")
var subMatch = re.FindStringSubmatch(user.AvatarUrl)
if len(subMatch) < 2 {
re := regexp.MustCompile("avatars/(.*).gif")
subMatch = re.FindStringSubmatch(user.AvatarUrl)
}

user.AvatarId = subMatch[1]

The subMatch[1] result in an index out of bound, this need to be fix

[rafiramadhana]

Hi @ArmandBriere , I am interested to work on this.

But some questions:

• Do we expect user.AvatarId to be left unset (i.e. empty string) on user without avatarUrl?
• Could you provide an example of valid user.AvatarUrl? I need this for the unit test

Thanks!