test-pr-comment-delivery: adjust it to the output of get-webhook-event-payload.js

I already adjusted it at some stage, but forgot that I had manually
modified the output of the `get-webhook-event-payload.js` script in my
tests, and it was therefore lacking the `id` and `action` lines.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

test-pr-comment-delivery.js

@@ -4,7 +4,7 @@
     const fs = require('fs')
 
     // Expect a path as command-line parameter that points to a file containing
-    // an event copy/pasted from
+    // the output of `get-webhook-event-payload.js`, or an event copy/pasted from
     // https://github.com/organizations/git-for-windows/settings/apps/gitforwindowshelper/advanced
     // in the form:
     //
@@ -20,7 +20,10 @@
     // }
 
     const path = process.argv[2]
-    const contents = fs.readFileSync(path).toString('utf-8')
+    const contents = fs
+        .readFileSync(path)
+        .toString('utf-8')
+        .replace(/^((id|action): .*\n)*/g, "")
 
     const req = {
         headers: {}