update changelog

Author: dirixmjm

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Ongoing
 
 - PR [337](https://github.com/plugwise/python-plugwise-usb/pull/337): Improve node removal, remove and reset the node as executed by Source, and remove the cache-file.
+- PR [341](https://github.com/plugwise/python-plugwise-usb/pull/341): Schedule clock synchronization every 3600 seconds
 - PR [342](https://github.com/plugwise/python-plugwise-usb/pull/342): Improve node_type chaching.
 - PR [343](https://github.com/plugwise/python-plugwise-usb/pull/343): Improve writing of cache-files.
 - PR [344](https://github.com/plugwise/python-plugwise-usb/pull/344): Don't store plus-device in nodetypes cache