patch 9.1.1417: missing info about register completion in complete_info()

Problem:  missing info about register completion in complete_info()
          (after v9.1.1408)
Solution: update documentation and mention that register is used as
          source, add a test (glepnir)

closes: #17389

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 6941380..3885bcb 100644
--- a/src/version.c
+++ b/src/version.c
@@ -710,6 +710,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1417,
+/**/
     1416,
 /**/
     1415,