Retry up to 5 times, when an error occurs.

http.c

@@ -22,6 +22,7 @@ char* request(char *url)
 	if(httpHandler) {
 		curl_easy_setopt(httpHandler,CURLOPT_URL, url);
 		curl_easy_setopt(httpHandler,CURLOPT_WRITEFUNCTION, httpResponseCallback);
+		curl_easy_setopt(httpHandler,CURLOPT_USERAGENT, "cWikiBot/0.1 (https://git.zom.bi/cpp/cWikiBot; cpp@zom.bi) libcurl4/7.64.0");
 		curl_easy_setopt(httpHandler,CURLOPT_WRITEDATA, (void *)&httpResponse);
 		return_code = curl_easy_perform(httpHandler);
 	}

lichess.c

@@ -12,14 +12,18 @@ json_object* query_lichess(char* username)
 	 */
 	char* api_base = "https://lichess.org/api/user/";
 	char user_url[128];
+	int retries = 5;
 	strcpy(user_url,api_base);
 	strcat(user_url,username);
 	printf("querying %s\n",user_url);
 	char* http_response = request(user_url);
-	if(http_response == NULL)
+	while(http_response == NULL)
 	{
 		printf("didn't receive HTTP response, we might be rate-limited. Waiting 60s");
 		sleep(60);
+		http_response = request(user_url);
+		retries--;
+		if(retries == 0)
 			return NULL;
 	}
 	json_object *lichessUser = json_tokener_parse(http_response);