Remove unnecessary tests to delete

The delete operator can be called on a null pointer, so there's no
reason for these tests.

obs/window-basic-main.cpp

@@ -550,9 +550,7 @@ OBSBasic::~OBSBasic()
 	 * can be freed, and we have no control over the destruction order of
 	 * the Qt UI stuff, so we have to manually clear any references to
 	 * libobs. */
-	if (properties)
 	delete properties;
-	if (transformWindow)
 	delete transformWindow;
 
 	ClearVolumeControls();