patch 8.0.0221: unnecessary condition on PROTO

Problem:    Checking if PROTO is defined inside a function has no effect.
Solution:   Remove the check for PROTO. (Hirohito Higashi)
diff --git a/src/version.c b/src/version.c
index 84cb940..5cca034 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    221,
+/**/
     220,
 /**/
     219,