patch 8.1.0873: list if distributed files does not include matchit autoload

Problem:    List if distributed files does not include the matchit autoload
            directory.
Solution:   Add the directory.
diff --git a/src/version.c b/src/version.c
index 71fd1c1..888bc25 100644
--- a/src/version.c
+++ b/src/version.c
@@ -784,6 +784,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    873,
+/**/
     872,
 /**/
     871,