Fixed typo in PresetComboBox.hpp and added missed include in libslic3r.h

src/libslic3r/libslic3r.h

@@ -5,6 +5,7 @@
 
 // this needs to be included early for MSVC (listing it in Build.PL is not enough)
 #include <memory>
+#include <array>
 #include <algorithm>
 #include <ostream>
 #include <iostream>

src/slic3r/GUI/PresetComboBoxes.hpp

@@ -13,7 +13,7 @@
 
 class wxString;
 class wxTextCtrl;
-class wxStatictext;
+class wxStaticText;
 class ScalableButton;
 
 namespace Slic3r {