Fixed normal bug EXT-6757 (The whole My inventory area becomes selected if an object has been drug&dropped from Trash folder)

Reason: LLFoldefView has set ShowSelectionContext attribute when drag is started. And selected item is shown with filled selection after item is dropped until mouse is over inventory panel.
In case of drag from Trash that item removes from inventory and selected item is the whole My Inventory folder. So, it is shown with filled selection.

To fix this bug it is necessary to call setShowSelectionContext(FALSE);
Implemented  in LLFolderView::onMouseLive() handler.

Reviewed by Richard Nelson at https://codereview.productengine.com/secondlife/r/275/

--HG--
branch : product-engine

indra/newview/llfolderview.h

@@ -230,6 +230,7 @@ public:
 								   EAcceptance* accept,
 								   std::string& tooltip_msg);
 	/*virtual*/ void reshape(S32 width, S32 height, BOOL called_from_parent = TRUE);
+	/*virtual*/ void onMouseLeave(S32 x, S32 y, MASK mask) { setShowSelectionContext(FALSE); }
 	virtual void draw();
 	virtual void deleteAllChildren();