multi: Fix wrong usage of mroute_extract_openvpn_sockaddr

maddr.proto needs to be set before the call since that
will change the behavior.

Found by GCC "'maddr.proto' is used uninitialized"

Change-Id: I76babf08b041162ddedf7a9b7c2799847f15cbdc
Signed-off-by: Frank Lichtenheld <[email protected]>
Acked-by: Gert Doering <[email protected]>
Acked-by: Gianmarco De Gregori <[email protected]>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1292
Message-Id: <[email protected]>
URL: https://www.mail-archive.com/[email protected]/msg33830.html
Signed-off-by: Gert Doering <[email protected]>

Author: flichtenheld

src/openvpn/multi.c

@@ -3965,9 +3965,9 @@ management_callback_kill_by_addr(void *arg, const in_addr_t addr, const int port
     saddr.addr.in4.sin_family = AF_INET;
     saddr.addr.in4.sin_addr.s_addr = htonl(addr);
     saddr.addr.in4.sin_port = htons(port);
+    maddr.proto = proto;
     if (mroute_extract_openvpn_sockaddr(&maddr, &saddr, true))
     {
-        maddr.proto = proto;
         hash_iterator_init(m->iter, &hi);
         while ((he = hash_iterator_next(&hi)))
         {