ol-notmuch.el first line, incorrect filename: org-notmuch.el

[Duianto -]

Problem:
The first line of `ol-notmuch.el` shows the filename as: `org-notmuch.el`
https://code.orgmode.org/bzg/org-mode/src/3a6061e787efc9793ce1b7445a1f2502f679b40e/contrib/lisp/ol-notmuch.el#L1

Cause:
It was overlooked when the other instances in the same file, were
renamed in this commit:
https://code.orgmode.org/bzg/org-mode/commit/499c0a50cc4b11e37b91374af23cb27ab8fc20d2#diff-6c345091b7fe5d259065a88d401cb738915e6f4R1

Solution:
Before:
;;; org-notmuch.el --- Links to notmuch messages

After:
;;; ol-notmuch.el --- Links to notmuch messages