After calling filter_for_query() the extra_replica to speculate to may
be left default-initialized which is :0 ipv6 address. Later below this
address is used as-is to check if it belongs to the same DC or not which
is not nice, as :0 is not an address of any existing endpoint.
Recent move of dc/rack data onto topology made this place reveal itself
by emitting the internal error due to :0 not being present on the
topology's collection of endpoints. Prior to this move the dc filter
would count :0 as belonging to "default_dc" datacenter which may or may
not match with the dc of the local node.
The fix is to explicitly tell set extra_replica from unset one.
fixes: #11825
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#11833