Don't automatically select all control handle in the vector clip tool

This was originally done because there was no easy way to select them
all otherwise, but box selection of handles has been supported for a
while now.

src/visual_tool_vector_clip.cpp

@@ -445,11 +445,4 @@ void VisualToolVectorClip::DoRefresh() {
 	spline.DecodeFromAss(vect);
 
 	MakeFeatures();
-	SelectAll();
-}
-
-void VisualToolVectorClip::SelectAll() {
-	sel_features.clear();
-	for (auto& feature : features)
-		sel_features.insert(&feature);
 }

src/visual_tool_vector_clip.h

@@ -45,7 +45,6 @@ class VisualToolVectorClip final : public VisualTool<VisualToolVectorClipDraggab
 	void Save();
 	void Commit(wxString message="") override;
 
-	void SelectAll();
 	void MakeFeature(size_t idx);
 	void MakeFeatures();