patch 9.0.0852: crypt test is skipped if xxd is not found

Problem:    Crypt test is skipped if xxd is not found.
Solution:   Find xxd where it was supposed to be build.
diff --git a/src/version.c b/src/version.c
index cb95d2c..8056d66 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    852,
+/**/
     851,
 /**/
     850,