FactSystem: ParameterManager: Remove unused variables

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

src/FactSystem/ParameterManager.cc

@@ -66,11 +66,6 @@ const QHash<int, QString> _mavlinkCompIdHash {
     { MAV_COMP_ID_GPS2,     "GPS2" }
 };
 
-const char* ParameterManager::_jsonParametersKey =          "parameters";
-const char* ParameterManager::_jsonCompIdKey =              "compId";
-const char* ParameterManager::_jsonParamNameKey =           "name";
-const char* ParameterManager::_jsonParamValueKey =          "value";
-
 ParameterManager::ParameterManager(Vehicle* vehicle)
     : QObject                           (vehicle)
     , _vehicle                          (vehicle)

src/FactSystem/ParameterManager.h

@@ -186,11 +186,6 @@ private:
 
     Fact _defaultFact;   ///< Used to return default fact, when parameter not found
 
-    static const char* _jsonParametersKey;
-    static const char* _jsonCompIdKey;
-    static const char* _jsonParamNameKey;
-    static const char* _jsonParamValueKey;
-
     /* MavFTP */
     bool               _tryftp;
 };