patch 8.2.3197: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move a few more error messages to errors.h.
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 513306b..d9ec4a4 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -3596,7 +3596,7 @@
      */
     if (sandbox != 0)
     {
-	emsg(_(e_sandbox));
+	emsg(_(e_not_allowed_in_sandbox));
 	return TRUE;
     }
 #endif