fix(vendor.roborock): Fix S4 detection logic

[cmccambridge]

Type of change

Type A:

• Bug fix (non-breaking change which fixes an issue)
• Refactor/Code Cleanup
• Docs
• Capability implementation for existing core capability
• New robot implementation

Type B:

• New capability
• New core feature

Description (Type A)

Detection logic for the Roborock S4 / T4 was incorrect due to a typo. Fixing it :-)
Didn't file an issue for this, though I can if you want to track. Noticed it as latest dustbuilder doesn't load Valetudo successfully with this error:

root@rockrobo:~# VALETUDO_CONFIG_PATH=/mnt/data/valetudo_config.json /usr/local/bin/valetudo
[2021-03-03T17:29:38.987Z] [INFO] Loading configuration file: /mnt/data/valetudo_config.json
[2021-03-03T17:29:39.013Z] [INFO] Set Logfile to /tmp/valetudo.log
[2021-03-03T17:29:39.029Z] [ERROR] Error while initializing robot implementation. Shutting down  Error: Couldn't find a suitable ValetudoRobot implementation.
    at Function.autodetectRobotImplementation (/snapshot/Valetudo/lib/core/ValetudoRobotFactory.js:52:19)
    at Function.getRobotImplementation (/snapshot/Valetudo/lib/core/ValetudoRobotFactory.js:16:45)
    at new Valetudo (/snapshot/Valetudo/lib/Valetudo.js:28:62)
    at Object.<anonymous> (/snapshot/Valetudo/index.js:5:16)
    at Module._compile (internal/modules/cjs/loader.js:1198:30)
    at Module._compile (pkg/prelude/bootstrap.js:1327:32)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1218:10)
    at Module.load (internal/modules/cjs/loader.js:1047:32)
    at Function.Module._load (internal/modules/cjs/loader.js:935:14)
    at Function.Module.runMain (pkg/prelude/bootstrap.js:1375:12)

[cmccambridge]

@Hypfer want to be super clear: I haven't tested this yet as I'm still working on build process locally here... but the change looks so clear from the source that I wanted to send it your way for any initial feedback, and a read on whether it's so clear that we can simply merge the fix :)

[cmccambridge]

Belated follow up, but just got the build done end to end and tested on my S4, it does indeed work for the S4 😁

Thanks!