FIX: missed to delete texture

Jira: STUDIO-4574
Change-Id: I8884380158d3d20ce76a07cbcaa8531ab039357b
(cherry picked from commit 44f93d083f542d6151f727e98933131cf0fa4463)

src/slic3r/GUI/PartPlate.cpp

@@ -5148,8 +5148,10 @@ void PartPlateList::BedTextureInfo::TexturePart::update_buffer()
 
 void PartPlateList::BedTextureInfo::TexturePart::reset()
 {
-    if (texture)
+    if (texture) {
         texture->reset();
+        delete texture;
+    }
     if (buffer)
         delete buffer;
 }