nghttpx: Fix uninitialized errors found by coverity scan

src/shrpx_dns_resolver.cc

@@ -112,7 +112,8 @@ void stop_ev(struct ev_loop *loop,
 } // namespace
 
 DNSResolver::DNSResolver(struct ev_loop *loop)
-    : loop_(loop),
+    : result_{},
+      loop_(loop),
       channel_(nullptr),
       family_(AF_UNSPEC),
       status_(DNS_STATUS_IDLE) {

src/shrpx_http_downstream_connection.cc

@@ -175,6 +175,7 @@ HttpDownstreamConnection::HttpDownstreamConnection(
       ssl_ctx_(worker->get_cl_ssl_ctx()),
       group_(group),
       addr_(nullptr),
+      raddr_(nullptr),
       ioctrl_(&conn_.rlimit),
       response_htp_{0},
       initial_addr_idx_(initial_addr_idx) {}