Fix build with newer libxml; checked was removed in:
https://gitlab.gnome.org/GNOME/libxml2/-/commit/ce76ebfd1312459951d555ad9d87fb9a89eede55

Index: Source/Additions/GSXML.m
--- Source/Additions/GSXML.m.orig
+++ Source/Additions/GSXML.m
@@ -2671,10 +2671,6 @@ getEntityDefault(void *ctx, const xmlChar *name, BOOL 
                   return NULL;
                 }
               ret->owner = 1;
-              if (ret->checked == 0)
-                {
-                  ret->checked = 1;
-                }
             }
         }
     }