[LyX/master] Cmake build: Fix the invalid test for '-Wno-deprecated-copy' flag

[Jean-Marc Lasgouttes]

Le 29/09/2021 à 17:32, Kornel Benko a écrit :
> commit c26db650a1e93573e4c09d4612ad45ae1e219854
> Author: Kornel Benko <kornel at lyx.org>
> Date:   Wed Sep 29 17:53:50 2021 +0200
> 
>      Cmake build: Fix the invalid test for '-Wno-deprecated-copy' flag
>      
>      The original test was always successfull, even if the flag was invalid.
>      But checking for '-Wdeprecated-copy' instead yields to error if the warning does not exist.
>      Existent warning for 'deprecated-copy' implies that 'no-deprecated-copy' also exist.

Excellent idea. I stole it.

JMarc