global: start relying on http_client_request_abort(NULL) being a no-op

Cleanup performed with the following semantic patch:

	@@
	expression E;
	@@

	- if (E != NULL) {
	- 	http_client_request_abort(&E);
	- }
	+ http_client_request_abort(&E);

src/auth/auth-policy.c

@@ -236,8 +236,7 @@ void auth_policy_finish(struct policy_lookup_ctx *context)
 		const char *error ATTR_UNUSED;
 		(void)json_parser_deinit(&context->parser, &error);
 	}
-	if (context->http_request != NULL)
-		http_client_request_abort(&context->http_request);
+	http_client_request_abort(&context->http_request);
 	if (context->request != NULL)
 		auth_request_unref(&context->request);
 }

src/lib-http/http-client-connection.c

@@ -1726,8 +1726,7 @@ http_client_connection_disconnect(struct http_client_connection *conn)
 	conn->closing = TRUE;
 	conn->connected = FALSE;
 
-	if (conn->connect_request != NULL)
-		http_client_request_abort(&conn->connect_request);
+	http_client_request_abort(&conn->connect_request);
 
 	if (conn->incoming_payload != NULL) {
 		/* the stream is still accessed by lib-http caller. */

src/lib-oauth2/oauth2.c

@@ -71,8 +71,7 @@ oauth2_request_abort(struct oauth2_request **_req)
 	struct oauth2_request *req = *_req;
 	*_req = NULL;
 
-	if (req->req != NULL)
-		http_client_request_abort(&req->req);
+	http_client_request_abort(&req->req);
 	oauth2_request_free_internal(req);
 }
 

src/plugins/fts-solr/solr-connection.c

@@ -556,8 +556,7 @@ int solr_connection_post_end(struct solr_connection_post **_post)
 			ret = -1;
 		}
 	} else {
-		if (post->http_req != NULL)
-			http_client_request_abort(&post->http_req);
+		http_client_request_abort(&post->http_req);
 	}
 	i_free(post);
 

src/plugins/fts/fts-parser-tika.c

@@ -250,8 +250,7 @@ static int fts_parser_tika_deinit(struct fts_parser *_parser, const char **retri
 	   timeout to ioloop unnecessarily */
 	i_stream_unref(&parser->payload);
 	io_remove(&parser->io);
-	if (parser->http_req != NULL)
-		http_client_request_abort(&parser->http_req);
+	http_client_request_abort(&parser->http_req);
 	if (parser->ioloop != NULL) {
 		io_loop_set_current(parser->ioloop);
 		io_loop_destroy(&parser->ioloop);