patch 8.1.0855: cannot build xxd with MSVC 10

Problem:    Cannot build xxd with MSVC 10.
Solution:   Move declaration to start of block.
diff --git a/src/version.c b/src/version.c
index c119643..4080d5e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -784,6 +784,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    855,
+/**/
     854,
 /**/
     853,