patch 8.1.0326: screen dump does not consider NUL and space equal

Problem:    Screen dump does not consider NUL and space equal.
Solution:   Use temp variables instead of character from cell.
diff --git a/src/version.c b/src/version.c
index dfb0965..50c8a5e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    326,
+/**/
     325,
 /**/
     324,