Previously, the Emacs byte compiler produced the warning
the function `remove-if-not' might not be defined at runtime.
because we only required cl at compile-time (not runtime). This fixes
this warning by requiring cl at runtime, ensuring that the definition
of remove-if-not is available.
(require 'mm-view)
(require 'mm-decode)
(require 'json)
-(eval-when-compile (require 'cl))
+(require 'cl)
(defvar notmuch-command "notmuch"
"Command to run the notmuch binary.")