quagga: drop recipe

Quagga is no longer maintained since 2018[1]. Its official repository is
not even available[2].
As an alternative, users can use FRRouting[3] which has been added to
meta-networking[4].

[1] https://github.com/Quagga/quagga
[2] https://git.savannah.gnu.org/cgit/quagga.git
[3] https://frrouting.org
[4] https://git.openembedded.org/meta-openembedded/tree/meta-networking/recipes-protocols/frr

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-networking/recipes-core/packagegroups/packagegroup-meta-networking.bb

@@ -158,7 +158,6 @@ RDEPENDS:packagegroup-meta-networking-protocols = "\
     openl2tp \
     mdns \
     nopoll \
-    quagga \
     radiusclient-ng \
     tsocks \
     openlldp \