patch 8.2.1847: Vim9: using negative value for unsigned type

Problem:    Vim9: using negative value for unsigned type.
Solution:   Use zero instead of -1.
diff --git a/src/version.c b/src/version.c
index 06a51f6..b95e0e9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1847,
+/**/
     1846,
 /**/
     1845,