patch 9.0.0089: fuzzy argument completion doesn't work for shell commands

Problem:    Fuzzy argument completion doesn't work for shell commands.
Solution:   Check for cmdidx not being CMD_bang. (Yegappan Lakshmanan,
            closes #10769)

src/version.c

@@ -735,6 +735,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    89,
 /**/
     88,
 /**/