[glib-networking] Add warning that OpenSSL backend isn't ready for Linux distros

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 8e1d80c1e0fc52d17d08a21946fa4a86ec30e1db
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Jun 9 14:05:55 2020 -0500

    Add warning that OpenSSL backend isn't ready for Linux distros
    
    There are hacks in half the tests where this backend doesn't return the
    expected error code or doesn't work as expected. But Arch Linux has
    enabled it for some reason. Warn distros.
    
    I do hope to enable this backend by default in the future. For now, it's
    not there yet.

 meson_options.txt | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/meson_options.txt b/meson_options.txt
index 3a525dd..aaf6227 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,3 +1,6 @@
+# The OpenSSL backend is provided for systems where licensing considerations
+# prohibit use of certain dependencies of GnuTLS. General-purpose Linux distros
+# should leave it disabled. Please don't second-guess our defaults.
 option('gnutls', type: 'feature', value: 'auto', description: 'support for GnuTLS networking configration')
 option('openssl', type: 'feature', value: 'disabled', description: 'support for OpenSSL networking 
configration')
 option('libproxy', type: 'feature', value: 'auto', description: 'support for libproxy proxy configration')