Git commits in Moodle 3.9.0 by Adrian Hutchinson

commit 9b0b472dd603656e6c6be39b9fac9abb843cc023
Author: Adrian Hutchinson <adrian.hutchinson@mheducation.com>
Date:   Tue, 18 Feb 2020 01:29:38 +0800
Tag:    v3.9.0-beta

MDL-67072 mod_lti: OIDC additional login parameters

commit 9c66d72779c0e8f9e346c1159e3991bfc39b8720
Author: Adrian Hutchinson <adrian.hutchinson@mheducation.com>
Date:   Tue, 18 Feb 2020 01:25:14 +0800
Tag:    v3.9.0-beta

MDL-67988 mod_lti: remove padding from JWS base64url encoding