bug#30444: 26.0.90; browse-url-emacs sets default-directory to "https://"

[Damien Cassou]

1. emacs -Q
2. M-x browse-url-emacs RET https://gnu.org
3. C-h v default-directory

Actual: "https://";

Expected: a directory such as (1) Emacs' startup directory or (2) a
temporary directory.

In GNU Emacs 26.0.90 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.26)
 of 2018-01-08 built on luz4
Repository revision: 918a052a422c05b5f78fd7c702eb6e3ee189fa18
Windowing system distributor 'Fedora Project', version 11.0.11906000
System Description:     Fedora release 27 (Twenty Seven)

-- 
Damien Cassou
http://damiencassou.seasidehosting.st

"Success is the ability to go from one failure to another without
losing enthusiasm." --Winston Churchill