Prefer HTTPS to FTP and HTTP in documentation

Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gtkutil.h b/src/gtkutil.h
index f0f2981418c..f71f4bb0eda 100644
--- a/src/gtkutil.h
+++ b/src/gtkutil.h
@@ -15,7 +15,7 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
-along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef GTKUTIL_H
 #define GTKUTIL_H