httpserver/osv-gui: update to latest

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
monitoring-agent: Fix Boost ASIO error handling

If OSv image is started under QEMU without networking, it blows up as follows:

  [penberg@nero osv]$ qemu-system-x86_64 -hda build/release/usr.img -nographic
  OSv v0.16-10-g1d18311
  pthread_setcancelstate() stubbed
  /#
  /# Aborted

  [backtrace]
  0x0000000000444251 <osv::generate_signal(siginfo&, exception_frame*)+49>
  0x00000000004442ba <osv::handle_mmap_fault(unsigned long, int, exception_frame*)+26>
  0x000000000032ed13 <mmu::vm_fault(unsigned long, exception_frame*)+147>
  0x0000000000392199 <page_fault+105>
  0x0000000000391086 <???+3739782>
  0x0000100000cf0d83 <boost::asio::ip::basic_resolver_iterator<boost::asio::ip::tcp>::dereference() const+43>
  0x0000100000cedd13 <boost::asio::ip::basic_resolver_iterator<boost::asio::ip::tcp>::operator->() const+23>
  0x000010000587fa8e <monitoring_agent::client::getaddr(std::string const&)+424>
  0x000010000587efc3 <monitoring_agent::client::upload(std::string const&, std::string const&, unsigned int, std::string const&, std::string const&, std::string const&)+101>
  0x0000100005873644 <???+92747332>
  0x000010000586cc50 <???+92720208>
  0x0000000000410d4a <osv::application::run_main(std::string, int, char**)+266>
  0x00000000004124f7 <osv::application::run_main()+567>
  0x000000000020c048 <osv::application::main()+88>
  0x00000000004127c8 <???+4270024>
  0x000000000043f6d5 <???+4454101>
  0x00000000003ed867 <thread_main_c+39>
  0x0000000000392005 <???+3743749>
  QEMU: Terminated

Fix that by checking for all errors, not just 'host_not_found' when
resolving an address.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>