neomutt: fix STARTTLS

When smtps is used as a protocol, neomutt expects TLS but will if
STARTTLS should be used. When using STARTTLS, smtp has to be used as
protocol and `ssl_force_tls` is set.

See <https://neomutt.org/guide/optionalfeatures#2-1-%C2%A0starttls>.

tests/modules/programs/neomutt/hm-example.com-starttls-expected

@@ -0,0 +1,38 @@
+# Generated by Home Manager.
+set ssl_force_tls = yes
+set certificate_file=/etc/ssl/certs/ca-certificates.crt
+
+# GPG section
+set crypt_use_gpgme = yes
+set crypt_autosign = no
+set crypt_opportunistic_encrypt = no
+set pgp_use_gpg_agent = yes
+set mbox_type = Maildir
+set sort = "threads"
+
+# MTA section
+set smtp_pass="`password-command`"
+set smtp_url='smtp://home.manager@smtp.example.com'
+
+
+
+
+
+# MRA section
+set folder='/home/hm-user/Mail/hm@example.com'
+set from='hm@example.com'
+set postponed='+Drafts'
+set realname='H. M. Test'
+set record='+Sent'
+set spoolfile='+Inbox'
+set trash='+Trash'
+
+
+# Extra configuration
+color status cyan default
+
+
+unset signature
+# notmuch section
+set nm_default_uri = "notmuch:///home/hm-user/Mail"
+virtual-mailboxes "My INBOX" "notmuch://?query=tag%3Ainbox"