Issue #25689: Fix language in ftplib and nntplib docs

Original patch by Silent Ghost.

Doc/library/ftplib.rst

@@ -52,8 +52,7 @@ The module defines the following items:
    will be used). *source_address* is a 2-tuple ``(host, port)`` for the socket
    to bind to as its source address before connecting.
 
-   :class:`FTP` class supports the :keyword:`with` statement. Here is a sample
-   on how using it:
+   The :class:`FTP` class supports the :keyword:`with` statement, e.g.:
 
     >>> from ftplib import FTP
     >>> with FTP("ftp1.at.proftpd.org") as ftp:

Doc/library/nntplib.rst

@@ -69,9 +69,9 @@ The module itself defines the following classes:
    connecting to an NNTP server on the local machine and intend to call
    reader-specific commands, such as ``group``.  If you get unexpected
    :exc:`NNTPPermanentError`\ s, you might need to set *readermode*.
-   :class:`NNTP` class supports the :keyword:`with` statement to
+   The :class:`NNTP` class supports the :keyword:`with` statement to
    unconditionally consume :exc:`OSError` exceptions and to close the NNTP
-   connection when done. Here is a sample on how using it:
+   connection when done, e.g.:
 
     >>> from nntplib import NNTP
     >>> with NNTP('news.gmane.org') as n: