message: support Starting HTTP/2 with Prior Knowledge over plain tcp connection
diff: @@ -119,10 +119,6 @@ extern swoole_object_array swoole_objects;
  #ifndef HAVE_OPENSSL
  #error "Enable openssl support, require openssl library."
  #endif
  -#else
  -#ifdef SW_USE_HTTP2
  -#error "Enable http2 support, require --enable-openssl."
  -#endif
  #endif
  #ifdef SW_SOCKETS
  @@ -138,9 +134,6 @@ extern swoole_object_array swoole_objects;
  #if !defined(HAVE_NGHTTP2)
  #error "Enable http2 support, require nghttp2 library."
  #endif
  -#if !defined(HAVE_OPENSSL)
  -#error "Enable http2 support, require openssl library."
  -#endif
  #endif
  #include "php7_wrapper.h"
  