inhuman/msite: cache/cache.go; 3 LoC

Found a possible issue in [inhuman/msite](https://www.github.com/inhuman/msite) at [cache/cache.go](https://github.com/inhuman/msite/blob/7575feeeb5bcde697e2c5fc78260216baae351ef/cache/cache.go#L17-L19)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first issue it finds, so please do not limit your consideration to the contents of the below message.

> reference to usr is reassigned at line 18

[Click here to see the code in its original context.](https://github.com/inhuman/msite/blob/7575feeeb5bcde697e2c5fc78260216baae351ef/cache/cache.go#L17-L19)

Click here to show the 3 line(s) of Go which triggered the analyzer.

```go
for _, usr := range usrs {
tokensCached[user.GetUserToken(&usr)] = &usr
}

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: 7575feeeb5bcde697e2c5fc78260216baae351ef

Read cache/cache.go at lines 17-19 and inspect the surrounding loop and user-token lookup. Determine whether the reported range-variable reference is a real defect, then classify the finding as Bug, Mitigated, or Desirable Behavior using the linked classification guidance and leave the corresponding reaction.

Written by the indexing model from the issue text.