remove old tools/update-subresource-integrity.py script which isn't used now...

remove old tools/update-subresource-integrity.py script which isn't used now that we download all admin page remote assets during setup

tools/update-subresource-integrity.py

-#!/usr/bin/python3
-# Updates subresource integrity attributes in management/templates/index.html
-# to prevent CDN-hosted resources from being used as an attack vector. Run this
-# after updating the Bootstrap and jQuery <link> and <script> to compute the
-# appropriate hash and insert it into the template.
-
-import re, urllib.request, hashlib, base64
-
-fn = "management/templates/index.html"
-
-with open(fn, 'r') as f:
-	content = f.read()
-
-def make_integrity(url):
-	resource = urllib.request.urlopen(url).read()
-	return "sha256-" + base64.b64encode(hashlib.sha256(resource).digest()).decode('ascii')
-
-content = re.sub(
-	r'<(link rel="stylesheet" href|script src)="(.*?)" integrity="(.*?)"',
-	lambda m : '<' + m.group(1) + '="' + m.group(2) + '" integrity="' + make_integrity(m.group(2)) + '"',
-	content)
-
-with open(fn, 'w') as f:
-	f.write(content)