patch 8.0.1037: "icase" of 'diffopt' is not used for highlighting

Problem:    "icase" of 'diffopt' is not used for highlighting differences.
Solution:   Also use "icase". (Rick Howe)
diff --git a/src/version.c b/src/version.c
index 579f0a2..8af4688 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1037,
+/**/
     1036,
 /**/
     1035,