Revert "nghttpx: Attempt to avoid TCP RST on socket closure on Linux"

This reverts commit f69b52b1aa.

src/shrpx_connection.cc

@@ -126,20 +126,7 @@ void Connection::disconnect() {
   }
 
   if (fd != -1) {
-    // At least for Linux, shutdown both sides, and continue to read
+    shutdown(fd, SHUT_WR);
-    // until it gets EOF or error in order to avoid TCP RST.
-    shutdown(fd, SHUT_RDWR);
-#ifdef __linux__
-    std::array<uint8_t, 16_k> b;
-    for (;;) {
-      ssize_t n;
-      while ((n = read(fd, b.data(), b.size())) == -1 && errno == EINTR)
-        ;
-      if (n <= 0) {
-        break;
-      }
-    }
-#endif // __linux__
     close(fd);
     fd = -1;
   }