fix(platform-webworker): remove trailing comma in package.json

Author: IgorMinar

modules/@angular/platform-webworker/package.json

@@ -9,7 +9,7 @@
   "license": "MIT",
   "peerDependencies": {
     "@angular/core": "0.0.0-PLACEHOLDER",
-    "@angular/platform-browser": "0.0.0-PLACEHOLDER",
+    "@angular/platform-browser": "0.0.0-PLACEHOLDER"
   },
   "repository": {
     "type": "git",