patch 8.0.0199: compiler warnings for libcall

Problem:    Warning for an unused parameter when the libcall feature is
            disabled.  Warning for a function type cast when compiling with
            -pedantic.
Solution:   Add UNUSED.  Use a different type cast. (Damien Molinier)
diff --git a/src/version.c b/src/version.c
index d826cb3..50bcce0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    199,
+/**/
     198,
 /**/
     197,