`-Werror` flag usually causes build failures due to minor changes in
compiler versions. They might be useful for developers themselves but
are rarely useful for distributions.
For example right now `cppunit` fails to compile on `gcc-13` due to a
`gcc` infelicity: https://gcc.gnu.org/PR107488
While this concrete instance is a compiler bug generally `-Werror` makes
users' lives harder. Specific `-Werror=<foo>` are better way to prevent
certain classes of bugs.
The change removes planket `-Werror` with `--disable-werror` flag.
86e8528f27