I'm storing e-mail addresses within some user nodes that I'm trying to match against, however the `(?i)` case-insensitive option doesn't appear to work when a `+` is added in the mail address. I use these to test, for example `john+business@doe.com`.

Setting up test nodes:

```
CREATE (uWithoutSymbol:USER {
    email: 'john@doe.com'
})
CREATE (uWithSymbol:USER {
    email: 'john+business@doe.com'
})

```

The Cypher queries:

```
MATCH (u:USER)
// This works
WHERE u.email =~ '(?i)john@doe.com'
RETURN u

MATCH (u:USER)
// This returns nothing
WHERE u.email =~ '(?i)john+business@doe.com'
RETURN u

```

I tried going for the case-insensitive unicode one: `(?ui)`, but also no luck. Any ideas?