core: 计量尝试人数而非提交量

suggested by @Menci

packages/hydrooj/src/handler/problem.ts

@@ -257,7 +257,7 @@ export class ProblemSubmitHandler extends ProblemDetailHandler {
         const rdoc = await record.get(domainId, rid);
         if (!pretest) {
             await Promise.all([
-                problem.inc(domainId, this.pdoc.docId, 'nSubmit', 1),
+                this.psdoc?.rid ? Promise.resolve() : problem.inc(domainId, this.pdoc.docId, 'nSubmit', 1),
                 problem.incStatus(domainId, this.pdoc.docId, this.user._id, 'nSubmit', 1),
                 domain.incUserInDomain(domainId, this.user._id, 'nSubmit'),
             ]);