Adding a new directory throws error if there is trailling whitespace

**Describe the bug**
It is not possible to add a new network / directory, when there is whitespace in the entry from the _homeserver_ dialog - the app displays error _URL non gérée_ (my phone's in French - roughly translated to _unhandled URL_).

**To Reproduce**
Steps to reproduce the behavior:
1. Go to '#' tab
2. Click on '#+'
3. Click on 'Switch'
4. Click on '+'
5. Type `libera.chat ` (note trailing space - in my case it was automatically added by autocorrect) and click OK
6. See error

**Expected behavior**
Trim leading/trailing whitespace to avoid such error

**Screenshots**
None

**Smartphone (please complete the following information):**
- Device: iPhone 6s
- OS: iOS 14.4.2
- Browser: N/A
- Version: 1.3.9

**Additional context**
As discussed in [Element IOS chat room](https://matrix.to/#/!pMBteVpcoJRdCJxDmn:matrix.org/$xlimts9PUc7YHmR9jftCf9P4YSdeLgARnCaJDwyn2M8?via=matrix.org&via=ergaster.org&via=librem.one)