patch 9.1.0473: term_start() does not clear vertical modifier

Problem:  term_start() does not clear vertical modifier
Solution: Clear the flag after splitting the window
          (Yegappan Lakshmanan)

closes: #14953

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 334ebd7..78668ea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    473,
+/**/
     472,
 /**/
     471,