patch 8.0.0446: the ";" command does not work after some characters

Problem:    The ";" command does not work after characters with a lower byte
            that is NUL.
Solution:   Properly check for not having a previous character. (Hirohito
            Higashi)
diff --git a/src/version.c b/src/version.c
index 7a0d500..cb416dc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,10 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    446,
+/**/
+    446,
+/**/
     445,
 /**/
     444,