ppp: update to version 2.4.8.git-2020-03-21

ppp: update to version 2.4.8.git-2020-03-21

Use upstream latest git HEAD as it allows to remove the patches
700-radius-Prevent-buffer-overflow-in-rc_mksid,
701-pppd-Fix-bounds-check-in-EAP-code and
702-pppd-Ignore-received-EAP-messages-when-not-doing-EAP and
take in other fixes.

41a7323 pppd: Fixed spelling 'unkown' => 'unknown' (#141)
6b014be pppd: Print version information to stdout instead of stderr (#133)
cba2736 pppd: Add RFC1990 (Multilink) to the See Also section of the man page
f2f9554 pppd: Add mppe.h to the list of headers to install if MPPE is defined
ae54fcf pppd: Obfuscate password argument string
8d45443 pppd: Ignore received EAP messages when not doing EAP
8d7970b pppd: Fix bounds check in EAP code
858976b radius: Prevent buffer overflow in rc_mksid()

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>