Disable building of Audio library in Native Client for now.

We now support NaCl 25, which doesn't have bundled OpenAL and I don't
feel like bumping the version to 27 yet.

PKGBUILD-nacl-newlib

@@ -20,6 +20,7 @@ build() {
         -DCMAKE_TOOLCHAIN_FILE="$startdir/toolchains/generic/NaCl-newlib-x86-32.cmake" \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_INSTALL_PREFIX=/usr/nacl \
+        -DWITH_AUDIO=OFF \
         -DWITH_MAGNUMINFO=ON \
         -DWITH_NACLAPPLICATION=ON \
         -DWITH_WINDOWLESSNACLAPPLICATION=ON \
@@ -35,6 +36,7 @@ build() {
         -DCMAKE_TOOLCHAIN_FILE="$startdir/toolchains/generic/NaCl-newlib-x86-64.cmake" \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_INSTALL_PREFIX=/usr/nacl \
+        -DWITH_AUDIO=OFF \
         -DWITH_MAGNUMINFO=ON \
         -DWITH_NACLAPPLICATION=ON \
         -DWITH_WINDOWLESSNACLAPPLICATION=ON