patch 9.0.1746: vim9class compile error for char/char_u conversion

Problem: vim9class compile error for char/char_u conversion
Solution: Correctly cast to (char *)

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 05e7e03..8f0db98 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1746,
+/**/
     1745,
 /**/
     1744,