"First shared hypercore must be the same" when trying to replicate via webrtc.

Nobody has claimed this yet.

I'm trying to replicate a db over `webrtc-swarm` and always running into the dreaded "First shared hypercore must be the same" message.

Below is the code I am trying to use. I use the same key for both dbs, and as far as i can tell i am looping both replication streams similarly to the tcp example in #19 .

Does anyone notice anything I'm doing wrong?

```javascript
const wrtc = require('wrtc')
const swarm = require('webrtc-swarm')

const signalhub = require('signalhub')
const hyperdb = require('hyperdb')

const db1 = init_db('./db1', { valueEncoding: 'utf-8' })

db1.on('ready', () => {
const db2 = init_db('./db2', db1.key, { valueEncoding: 'utf-8' })
db2.on('ready', () => {
db1.put('/hello', 'world', () => {
init_swarm(db1, (hub) => {
return swarm(hub, {
wrtc: wrtc
})
})
init_swarm(db2, (hub) => {
return swarm(hub, {
wrtc: wrtc
})
})
})

})
})

function init_swarm(db, swarmfn) {
const hub = signalhub('freemate', ['https://signalhub.mafintosh.com'])

const sw = swarmfn(hub)

sw.on('peer', (peer, id) => {
console.log('found peer')
const repstream = db.replicate()
peer.on('data', (data) => {
console.log('id: ', id, ' got data: ', data)
})
repstream.pipe(peer).pipe(repstream)
peer.once('finish', (err) => console.log(err))
peer.once('error', (err) => console.log(err))
})

return sw
}

function init_db(location) {
const db = hyperdb(location, { valueEncoding: 'utf-8' })
return db
}
```

Start by reproducing the provided hyperdb, webrtc-swarm, signalhub, and wrtc setup, then compare the replication stream wiring with the TCP example referenced in #19. Trace why the two databases are rejected despite using the same key; done means the same-key databases replicate without the “First shared hypercore must be the same” error.

Written by the indexing model from the issue text.