fix(ssl): enable partial write on SSL context

This patch enables the partial write mode on the SSL server context,
giving us "normal" behavior on non-blocking sockets.
Signed-off-by: Louis Solofrizzo <lsolofrizzo@scaleway.com>

src/server/listener.cc

@@ -138,6 +138,7 @@ namespace Pistache::Tcp
                 throw std::runtime_error(err);
             }
 
+            SSL_CTX_set_mode(GetSSLContext(ctx), SSL_MODE_ENABLE_PARTIAL_WRITE);
             return ctx;
         }