Try to fix Dockerfile: Create directory for node-gyp.

Thanks to xet7 !

Dockerfile

@@ -171,6 +171,7 @@ RUN \
     mv node-${NODE_VERSION}-${ARCHITECTURE} /opt/nodejs && \
     ln -s /opt/nodejs/bin/node /usr/bin/node && \
     ln -s /opt/nodejs/bin/npm /usr/bin/npm && \
+    mkdir -p /opt/nodejs/lib/node_modules/fibers/.node-gyp && \
     \
     #DOES NOT WORK: paxctl fix for alpine linux: https://github.com/wekan/wekan/issues/1303
     #paxctl -mC `which node` && \