Do not turn some compiler warnings into errors by default. This part was
copied from openbsc.git 34f012 ("Turn some compiler warnings into
errors"), where it was added before --enable-werror was available.
We build with --enable-werror during development and in CI. If the code
is built with a different compiler that throws additional warnings, it
should not stop the build.
Related: OS#5289
Change-Id: Ib5602017545d68f0fdb0b4df7ed3087a2cb1775c
Harald Welte
Oliver Smith