Fixed unreferenced parameter warning.

Parameter xmpData was unused in wxImage::Create when compiling with wxUSE_XPM set to 0.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70022 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/image.cpp

@@ -142,6 +142,7 @@ bool wxImage::Create(const char* const* xpmData)
     (*this) = decoder.ReadData(xpmData);
     return IsOk();
 #else
+    wxUnusedVar(xpmData);
     return false;
 #endif
 }