[patches] Update istl patch to 2.6
See merge request !1454 (merged)
(cherry picked from commit 4c6adfa4)
d7803af7 [patches] Update istl patch to 2.6
[patches] Update istl patch to 2.6 See merge request !1454 (cherry picked from commit 4c6adfa4) d7803af7 [patches] Update istl patch to 2.6