patch 8.1.0562: parsing of 'diffopt' is slightly wrong

Problem:    Parsing of 'diffopt' is slightly wrong.
Solution:   Fix the parsing and add a test. (Jason Franklin, Christian
            Brabandt)
diff --git a/src/version.c b/src/version.c
index cbe4636..f86f7c9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    562,
+/**/
     561,
 /**/
     560,