If you’re running the latest emonSD (03May16), this has now been fixed. As long as you run admin > emonpi update to pull in the latest changes it’s fine (and highly recommended to fix Dirty Cow) to update to mosquito 1.4.10 by running sudo apt-get update && upgrade 
.
The issue was Mosquito 1.4.10 now requires a log file to be created. This has now been added to rc.local which runs at boot. The rc.local_jessieminimal in the emonp repo ~/emonpi is symlinked to /etc/rc.local on the emonSD.