Remove incorrect comment

src/FactSystem/FactSystem.h

@@ -20,10 +20,6 @@
 
 /// The components of the FactSystem are a Fact which holds an individual value. FactMetaData holds
 /// additional meta data associated with a Fact such as description, min/max ranges and so forth.
-/// The FactValidator object is a QML validator which validates input according to the FactMetaData
-/// settings. Client code can then use this system to expose sets of Facts to QML code. An example
-/// of this is the PX4ParameterMetaData onbject which is part of the PX4 AutoPilot plugin. It exposes
-/// the firmware parameters to QML such that you can bind QML ui elements directly to parameters.
 
 class FactSystem : public QGCTool
 {