ca-certificates: change SRC_URI from Debian anonscm to salsa

ca-certificates: change SRC_URI from Debian anonscm to salsa

Debian anonscm service in Alioth is shutdown and thus
fetching ca-certificates sources fails.

https://wiki.debian.org/Alioth

"Alioth is broken, and there is nobody around to fix it. Don't ask the remaining people who give it life support to implement fixes and changes. It is being replaced by a cocktail of ?GitLab (see Salsa), read-only repos and keep-alive mechanisms. See below for more information."

(From OE-Core rev: fc20ff2003cee7ee3b78ba3bc236a60a8caabc35)

Signed-off-by: Mikko Rapeli <mikko.rapeli@bmw.de>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>