don't compare initial slider position with uninitialized m_pos (modified patch 1818759)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49355 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/slider.h

@@ -58,7 +58,7 @@ public:
 
     static wxVisualAttributes
     GetClassDefaultAttributes(wxWindowVariant variant = wxWINDOW_VARIANT_NORMAL);
-    
+
     // implementation
     double m_pos;
     int m_scrollEventType;
@@ -68,6 +68,9 @@ public:
 protected:
     virtual GdkWindow *GTKGetWindow(wxArrayGdkWindows& windows) const;
 
+    // set the slider value unconditionally
+    void GTKSetValue(int value);
+
     DECLARE_DYNAMIC_CLASS(wxSlider)
 };