patch 8.1.1873: cannot build tiny version

Problem:    Cannot build tiny version.
Solution:   Remove #ifdef for is_autocmd_blocked().
diff --git a/src/version.c b/src/version.c
index 5d7da51..081e84a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1873,
+/**/
     1872,
 /**/
     1871,