fix for crash: invalid HTTP version

server_http.hpp

@@ -739,12 +739,17 @@ namespace SimpleWeb {
                 return;
               }
             }
+	    try{
             if(std::stof(response->session->request->http_version) >= 1.1) {
               auto new_session = std::make_shared<Session>(this->config.max_request_streambuf_size, response->session->connection);
               this->read(new_session);
               return;
             }
 	    }
+	    catch(const std::out_of_range& e) {
+		    std::cerr << "invalid HTTP version" << e.what() << '\n';
+	    }
+          }
           else if(this->on_error)
             this->on_error(response->session->request, ec);
         });