Use base url for return url after deleting a repo

Change-Id: I1d1a9b6a7744b8427297d57a7684d207436570cd
diff --git a/web/gr-delete-repo.ts b/web/gr-delete-repo.ts
index 00bc08e..5a2ece1 100644
--- a/web/gr-delete-repo.ts
+++ b/web/gr-delete-repo.ts
@@ -33,6 +33,9 @@
   interface HTMLElementTagNameMap {
     'gr-delete-repo': GrDeleteRepo;
   }
+  interface Window {
+    CANONICAL_PATH?: string;
+  }
 }
 
 @customElement('gr-delete-repo')
@@ -163,11 +166,15 @@
       .then(_ => {
         this.plugin.restApi().invalidateReposCache();
         this.deleteRepoOverlay?.close();
-        window.location.href = '/admin/repos';
+        window.location.href = `${this.getBaseUrl()}/admin/repos`;
       })
       .catch(e => {
         this.error = e;
         this.deleteRepoOverlay?.close();
       });
   }
+
+  private getBaseUrl() {
+    return window.CANONICAL_PATH || '';
+  }
 }