Fix for failing cpu detection during build

src/freedombone-utils-nodejs

 # have specifically the correct versions
 NODEJS_VERSION='8.11.1'
 NODEJS_N_VERSION='2.1.7'
-NPM_VERSION='5.8.0'
+NPM_VERSION='5.6.0'
 
 # This file keeps track of the apps needing nodejs
 # so that it can be removed if tere are no apps which need it
     get_npm_arch
 
     $mesh_install_nodejs_prefix npm config set unsafe-perm true
+    if [ -f "$rootdir/usr/lib/node_modules/npm/node_modules/worker-farm/lib/farm.js" ]; then
+        # fix for failing cpu detection during image build with qemu, see https://github.com/npm/npm/issues/19265
+        sed -i "s|require('os').cpus().length|1|g" "$rootdir/usr/lib/node_modules/npm/node_modules/worker-farm/lib/farm.js"
+    fi
     $mesh_install_nodejs_prefix npm install --arch=$NPM_ARCH -g npm@${NPM_VERSION} --save
     if [ -f "$rootdir/usr/local/bin/npm" ]; then
         cp "$rootdir/usr/local/bin/npm" /usr/bin/npm