patch 9.1.0863: getcellpixels() can be further improved

Problem:  getcellpixels() can be further improved
Solution: improve it further, add more tests
          (mikoto2000)

closes: #16047

Signed-off-by: mikoto2000 <mikoto2000@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 69b5416..d0aa403 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    863,
+/**/
     862,
 /**/
     861,