package/libqmi: switch to the new option to disable -Werror

package/libqmi: switch to the new option to disable -Werror

--enable-more-warnings has been dropped since version 1.26.0 and
https://github.com/freedesktop/libqmi/commit/9f31a45d5fc137431705d47b83669f35259932b4

Instead, a new --disable-Werror option has been added, through the use
of AX_COMPILER_FLAGS, so use that to explicitly request wrnings not be
treated as errors.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[yann.morin.1998@free.fr: use --disable-Werror instead of nothing]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>