libs: use jglobus-2.0.6-rc2

includes fixes for cert validation and race conditions
Acked-by: Paul Millar
Target: trunk, 2.6
Require-book: no
Require-notes: no
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>

(cherry-picked from 5b0c165b8ce69101afcb2ea071f457c5c52bda35)
Merge pull request #83 from gbehrmann/fix/2.2-sha2/rb5587

libs: use jglobus-2.0.6-rc2