patch 8.1.1872: when Vim exits because of a signal, VimLeave is not triggered

Problem:    When Vim exits because of a signal, VimLeave is not triggered.
            (Daniel Hahler)
Solution:   Unblock autocommands when triggering VimLeave. (closes #4818)
diff --git a/src/version.c b/src/version.c
index 1d1b3f6..5d7da51 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1872,
+/**/
     1871,
 /**/
     1870,