Update de_web_plugin.cpp
Update de_web_plugin.cpp

Samsumg SmartThings multipurpose sensor, see #1848:
- Add `config.duration`.
- Refactor logic  to update `state.vibration`.

dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin