CCC doesn't currently have i18n support.
What has made this bearable until now, is that all hard-coded things _can_ be changed through configuration of each chart, in its input options. 
However, the way this message is currently implemented, it cannot be configured. Even if were to be implemented in CCC, it would still need to be configured in the "ccc_wrapper.js", and a new resource string added to analyzer's resources.
These changes can probably be performed with small risk and in a small amount of time. I leave it to you to decide if you want it done, and if so, if this pull-request should be accepted anyway, and a new one be created for that specific correction.