patch 8.1.0109: new po makefile missing from distribution

Problem:    New po makefile missing from distribution.
Solution:   Add it to the file list.
diff --git a/src/version.c b/src/version.c
index a2363e2..00f3c0d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    109,
+/**/
     108,
 /**/
     107,