Improve text of manual plugin. (#4810)

certbot/plugins/manual.py

@@ -44,22 +44,14 @@ Please deploy a DNS TXT record under the name
 
 Before continuing, verify the record is deployed."""
     _HTTP_INSTRUCTIONS = """\
-Make sure your web server displays the following content at
-{uri} before continuing:
+Create a file containing just this data:
 
 {validation}
 
-If you don't have HTTP server configured, you can run the following
-command on the target server (as root):
+And make it available on your web server at this URL:
 
-mkdir -p /tmp/certbot/public_html/{achall.URI_ROOT_PATH}
-cd /tmp/certbot/public_html
-printf "%s" {validation} > {achall.URI_ROOT_PATH}/{encoded_token}
-# run only once per server:
-$(command -v python2 || command -v python2.7 || command -v python2.6) -c \\
-"import BaseHTTPServer, SimpleHTTPServer; \\
-s = BaseHTTPServer.HTTPServer(('', {port}), SimpleHTTPServer.SimpleHTTPRequestHandler); \\
-s.serve_forever()" """
+{uri}
+"""
 
     def __init__(self, *args, **kwargs):
         super(Authenticator, self).__init__(*args, **kwargs)