svx: fix crash in JunitTest_svx_unoapi

618fd9d9 added a mpLBColor widget with
a type that does not match what is in the .ui file.

Change-Id: I17c58448c1d6cf43652702d60d5600ce8de64224

svx/source/sidebar/line/LinePropertyPanel.hxx

@@ -23,6 +23,7 @@
 #include <vcl/ctrl.hxx>
 #include <sfx2/sidebar/SidebarPanelBase.hxx>
 #include <sfx2/sidebar/ControllerItem.hxx>
+#include <sfx2/sidebar/SidebarToolBox.hxx>
 #include <vcl/fixed.hxx>
 #include <vcl/field.hxx>
 #include <vcl/layout.hxx>
@@ -97,7 +98,7 @@ private:
     VclPtr<FixedText>   mpFTWidth;
     VclPtr<ToolBox>     mpTBWidth;
     VclPtr<FixedText>   mpFTColor;
-    VclPtr<ListBox>     mpLBColor;
+    VclPtr<sfx2::sidebar::SidebarToolBox> mpLBColor;
     VclPtr<FixedText>   mpFTStyle;
     VclPtr<ListBox>     mpLBStyle;
     VclPtr<FixedText>   mpFTTransparency;