uhttpd: always turn on TLS support, include ustream-ssl as a build dependency

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35295 3c298f89-4303-0410-b956-a3cf2f4a3e73
netifd: Fix a segfault when globals.ula_prefix is empty

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35296 3c298f89-4303-0410-b956-a3cf2f4a3e73