Download modern CA cert to use feeds normally without SSL issues

Dockerfile

@@ -56,9 +56,12 @@ RUN cd /home/builder/openwrt && \
     rm -f scripts/config/zconf.tab.c scripts/config/lex.yy.c && \
     make -C scripts/config conf
 
+RUN wget -q -O /etc/ssl/certs/ca-certificates.crt https://curl.se/ca/cacert.pem && \
+        update-ca-certificates --fresh
+
 RUN cd /home/builder/openwrt && \
-    wget https://github.com/openwrt/packages/archive/master.tar.gz -O - | tar xz -C feeds/ && \
-    mv feeds/packages-master feeds/packages
+        ./scripts/feeds update -a && \
+        ./scripts/feeds install -a
 
 RUN chown -R builder:builder /home/builder/openwrt