Update Transmit cask to v4.4.1 from v4.4.0

This patch updates the version of Transmit to version 4.4.1 from the
current version of 4.4.0. It includes a new checksum, version, and URL.

Audit:
```sh
❯ brew cask audit transmit
audit for transmit: passed
```
Merge pull request #673 from ciarand/update-transmit-to-v4.1.1

Update Transmit cask to v4.4.1 from v4.4.0