Remove errFn from createGroup

Change-Id: I448e054fee4e0e92e9e2534afc761437196e8232
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
index d72225e..7b090cc 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
@@ -445,24 +445,12 @@
     });
   }
 
-  createGroup(config: GroupInput & {name: string}): Promise<Response>;
-
-  createGroup(
-    config: GroupInput & {name: string},
-    errFn: ErrorCallback
-  ): Promise<Response | undefined>;
-
-  createGroup(config: GroupInput, errFn?: ErrorCallback) {
-    if (!config.name) {
-      // TODO(TS): Fix return value
-      return '';
-    }
+  createGroup(config: GroupInput & {name: string}): Promise<Response> {
     const encodeName = encodeURIComponent(config.name);
     return this._restApiHelper.send({
       method: HttpMethod.PUT,
       url: `/groups/${encodeName}`,
       body: config,
-      errFn,
       anonymizedUrl: '/groups/*',
     });
   }
diff --git a/polygerrit-ui/app/services/services/gr-rest-api/gr-rest-api.ts b/polygerrit-ui/app/services/services/gr-rest-api/gr-rest-api.ts
index 777402f..0c5af24 100644
--- a/polygerrit-ui/app/services/services/gr-rest-api/gr-rest-api.ts
+++ b/polygerrit-ui/app/services/services/gr-rest-api/gr-rest-api.ts
@@ -517,11 +517,6 @@
     | Promise<PathToCommentsInfoMap | undefined>;
 
   createGroup(config: GroupInput & {name: string}): Promise<Response>;
-  createGroup(
-    config: GroupInput & {name: string},
-    errFn: ErrorCallback
-  ): Promise<Response | undefined>;
-  createGroup(config: GroupInput, errFn?: ErrorCallback): Promise<Response>;
 
   getPlugins(
     filter: string,