Add a package: line to c-submit-bug-report.

* lisp/progmodes/cc-mode.el (c-submit-bug-report):
Add a Package: line for mail clients that do not support X- headers.
1 job for emacs-26 in 26 minutes and 24 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #1450
test

00:26:24