patch 8.2.2591: Poke files are not recognized

Problem:    Poke files are not recognized.
Solution:   Add a filetype entry. (Matt Ihlenfield)
diff --git a/src/version.c b/src/version.c
index 1eecf5d..76a95b9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2591,
+/**/
     2590,
 /**/
     2589,