Prefer setq-local in net/*.el

Prefer setq-local in net/*.el

* lisp/net/ange-ftp.el (ange-ftp-process-handle-line):
(internal-ange-ftp-mode):
* lisp/net/imap.el (imap-fetch-safe):
* lisp/net/net-utils.el (net-utils-mode):
(nslookup-mode, network-connection-mode-setup):
* lisp/net/newst-plainview.el (newsticker-mode):
(newsticker-buffer-update):
* lisp/net/newst-treeview.el (newsticker--treeview-item-show):
(newsticker-treeview-mode):
* lisp/net/rlogin.el (rlogin):
* lisp/net/secrets.el (secrets-mode):
* lisp/net/sieve-mode.el (sieve-mode):
* lisp/net/sieve.el (sieve-setup-buffer, sieve-open-server):
* lisp/net/snmp-mode.el (snmp-common-mode, snmp-mode, snmpv2-mode):
* lisp/net/telnet.el (telnet-mode):
* lisp/net/tramp.el (tramp-get-debug-buffer): Prefer setq-local.