patch 8.2.3015: Vim9: Assigning to @# requires a string

Problem:    Vim9: Assigning to @# requires a string. (Naohiro Ono)
Solution:   Accent a number or a string. (closes #8396)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index fabce4d..2577e63 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -2182,8 +2182,7 @@
 
 		    --ectx->ec_stack.ga_len;
 		    tv = STACK_TV_BOT(0);
-		    write_reg_contents(reg == '@' ? '"' : reg,
-						 tv_get_string(tv), -1, FALSE);
+		    write_reg_contents(reg, tv_get_string(tv), -1, FALSE);
 		    clear_tv(tv);
 		}
 		break;