socket: Add support for socket protcol

Now we don't support the socket protocol like
sctp and udplite .

This patch add a new config param
SocketProtocol: udplite/sctp

With this now we can configure the protocol as

udplite = IPPROTO_UDPLITE
sctp = IPPROTO_SCTP

Tested with nspawn:

1 files changed, 2 insertions, 0 deletions

diff --git a/src/core/socket.h b/src/core/socket.h
index 94cda8a90d..fb3948130f 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -120,6 +120,8 @@ struct Socket {
         bool remove_on_stop;
         bool writable;
 
+        int socket_protocol;
+
         /* Socket options */
         bool keep_alive;
         bool no_delay;