“Large” LibreOffice icons are 24 × 24 pixel, as you’d expect

The Galaxy theme was the only odd duck to use 26 × 26 pixel icons.
We’ve removed it, but the Change Icon dialog was still reporting
this misleading value.

Spotted by Rizal Muttaqin.

Change-Id: I4f82727b93239a32f7eab5473baa3b8705abde29
Reviewed-on: https://gerrit.libreoffice.org/69148
Tested-by: Jenkins
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>

cui/source/customize/cfg.cxx

@@ -2643,7 +2643,7 @@ SvxIconSelectorDialog::SvxIconSelectorDialog(weld::Window *pWindow,
 
     m_nExpectedSize = 16;
     if (SvxConfigPageHelper::GetImageType() & css::ui::ImageType::SIZE_LARGE)
-        m_nExpectedSize = 26;
+        m_nExpectedSize = 24;
     else if (SvxConfigPageHelper::GetImageType() & css::ui::ImageType::SIZE_32)
         m_nExpectedSize = 32;