bug#26986: 26.0.50; Unsafe recovery should be off by default in batch mode

[Eli Zaretskii]

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Thu, 18 May 2017 20:26:13 +0000
> Cc: 26986@debbugs.gnu.org
> 
>  I see your point, but what are the arguments for changing their values
>  in batch mode? IOW, what advantages will this give us?
> 
> When debugging Emacs internals or running unit tests, setting these variables 
> to nil will cause obvious and
> clear failures instead of silent recovery attempts. 

OK, but the batch mode is not used only for debugging or testing.
Perhaps we should change the values in these two cases.