fix self-signed cert notice from generate-config

fixes #4620

changelog.d/4625.bugfix

@@ -0,0 +1 @@
+fix self-signed cert notice from generate-config.

synapse/config/_base.py

@@ -257,7 +257,7 @@ class Config(object):
             "--keys-directory",
             metavar="DIRECTORY",
             help="Used with 'generate-*' options to specify where files such as"
-            " certs and signing keys should be stored in, unless explicitly"
+            " signing keys should be stored, unless explicitly"
             " specified in the config.",
         )
         config_parser.add_argument(
@@ -313,16 +313,11 @@ class Config(object):
                 print(
                     (
                         "A config file has been generated in %r for server name"
-                        " %r with corresponding SSL keys and self-signed"
-                        " certificates. Please review this file and customise it"
+                        " %r. Please review this file and customise it"
                         " to your needs."
                     )
                     % (config_path, server_name)
                 )
-                print(
-                    "If this server name is incorrect, you will need to"
-                    " regenerate the SSL certificates"
-                )
                 return
             else:
                 print(