patch 8.1.0890: pty allocation wrong if using file for out channel

Problem:    Pty allocation wrong if using file for out channel and using null
            for in channel and null for error channel.
Solution:   Correct using use_file_for_out in condition. (Ozaki Kiichi, closes
            #3917)

src/version.c

@@ -783,6 +783,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    890,
 /**/
     889,
 /**/