Fix Angular base href

frontend/angular.json

@@ -39,7 +39,6 @@
         "build": {
           "builder": "@angular-devkit/build-angular:browser",
           "options": {
-            "baseHref": "./",
             "outputPath": "../backend/dist-frontend",
             "index": "src/index.html",
             "main": "src/main.ts",

frontend/package.json

@@ -4,7 +4,7 @@
   "scripts": {
     "ng": "ng",
     "start": "ng serve",
-    "build": "ng build",
+    "build": "ng build --base-href=./",
     "watch": "ng build --watch --configuration development",
     "test": "ng test"
   },