Fix (unreported) bda locking of whole GP modifiers whem GP obdata is linked.

Only applys to obdata feature is supposed to be locked in that case, not
the whole modifier.

source/blender/editors/interface/interface_templates.c

@@ -2249,6 +2249,10 @@ static uiLayout *gpencil_draw_modifier(uiLayout *layout, Object *ob, GpencilModi
                 0,
                 "apply_as",
                 MODIFIER_APPLY_DATA);
+
+    UI_block_lock_clear(block);
+    UI_block_lock_set(block, ob && ID_IS_LINKED(ob), ERROR_LIBDATA_MESSAGE);
+
     uiItemO(row,
             CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Copy"),
             ICON_NONE,