patch 8.2.4427: getchar() may return modifiers if no character is available

Problem:    getchar() may return modifiers if no character is available.
Solution:   Do not process modifiers when there is no character. (closes #9806)
diff --git a/src/version.c b/src/version.c
index 6c5ca2b..c5f5c22 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4427,
+/**/
     4426,
 /**/
     4425,