后台：增加后台数据库表，修复连接问题

shared/db/GMGroup.ts

@@ -1,7 +1,7 @@
 import { COUNTER } from './../consts';
 import { CounterModel } from './Counter';
 import BaseModel from './BaseModel';
-import { index, getModelForClass, prop, DocumentType, modelOptions } from '@typegoose/typegoose';
+import { index, getModelForClass, prop, DocumentType, modelOptions, ReturnModelType, mongoose } from '@typegoose/typegoose';
 
 /**
   * GM用户组接口
@@ -74,8 +74,12 @@ export default class GMGroup extends BaseModel {
   
 }
 
-export const GMGroupModel = getModelForClass(GMGroup);
-
+export let GMGroupModel: ReturnModelType<typeof GMGroup, {}>;
+export function loadGMGroupModel(connect: mongoose.Connection) {
+  GMGroupModel = getModelForClass(GMGroup, {
+        existingConnection: connect
+    });
+}
 export interface GMGroupType extends Pick<DocumentType<GMGroup>, keyof GMGroup>{
   id: number;
 };