Keyframe: use = default to specify default constructor

Author: musteresel

include/KeyFrame.h

@@ -68,7 +68,7 @@ namespace openshot {
 	public:
 
 		/// Default constructor for the Keyframe class
-		Keyframe();
+		Keyframe() = default;
 
 		/// Constructor which sets the default point & coordinate at X=1
 		Keyframe(double value);

src/KeyFrame.cpp

@@ -42,10 +42,6 @@ Keyframe::Keyframe(double value) {
 	AddPoint(Point(value));
 }
 
-// Keyframe constructor
-Keyframe::Keyframe() {
-}
-
 // Add a new point on the key-frame.  Each point has a primary coordinate,
 // a left handle, and a right handle.
 void Keyframe::AddPoint(Point p) {