Merge pull request #4250 from OSGeo/backport-4248-to-9.5

[Backport 9.5] affine.rst: Fixed second s21 that should say s22

Author: rouault

docs/source/operations/transformations/affine.rst

@@ -26,7 +26,7 @@ This can be used to implement:
 
 - EPSG "Affine parametric transformation" of code 9624 by setting `A0`, `A1`, `A2`,
   `B0`, `B1`, `B2` EPSG parameters to respectively `xoff`, `s11`, `s12`, `yoff`,
-  `s21`, `s21` PROJ parameters.
+  `s21`, `s22` PROJ parameters.
 
 - EPSG "Similarity transformation" of code 9621 by setting: