Update issues URL in metadata.json

Author: mhashizume

metadata.json

@@ -6,7 +6,7 @@
   "license": "Apache-2.0",
   "source": "https://github.com/puppetlabs/puppetlabs-mailalias_core",
   "project_page": "https://github.com/puppetlabs/puppetlabs-mailalias_core",
-  "issues_url": "https://tickets.puppetlabs.com/projects/MODULES",
+  "issues_url": "https://github.com/puppetlabs/puppetlabs-mailalias_core/issues",
   "dependencies": [
 
   ],