Conf.example: Update recommended maximum cloud radius to 26

minetest.conf.example

@@ -143,7 +143,7 @@
 #enable_clouds = true
 #cloud_height = 120
 #    Radius of cloud area stated in number of 64 node cloud squares.
-#    Values > 22 will start to produce clipping of the cloud area corners.
+#    Values larger than 26 will start to produce sharp cutoffs at cloud area corners.
 #cloud_radius = 12
 #enable_3d_clouds = true
 #    Use a cloud animation for the main menu background