nghttpx: Workaround for Ubuntu 15.04 which does not value-initialize on std::make_shared.

src/shrpx_worker.cc

@@ -127,6 +127,11 @@ Worker::Worker(struct ev_loop *loop, SSL_CTX *sv_ssl_ctx, SSL_CTX *cl_ssl_ctx,
     dst.pattern = src.pattern;
 
     auto shared_addr = std::make_shared<SharedDownstreamAddr>();
+
+    // TODO for some reason, clang-3.6 which comes with Ubuntu 15.10
+    // does not value initialize SharedDownstreamAddr above.
+    *shared_addr = SharedDownstreamAddr{};
+
     shared_addr->addrs.resize(src.addrs.size());
     shared_addr->proto = src.proto;