fix(deps): update dependency @nestjs/jwt to v6

Author: renovate-bot

sample/19-auth/package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "@nestjs/common": "6.0.0",
     "@nestjs/core": "6.0.0",
-    "@nestjs/jwt": "0.3.0",
+    "@nestjs/jwt": "6.0.0",
     "@nestjs/platform-express": "6.0.0",
     "@nestjs/passport": "5.1.0",
     "passport": "0.4.0",