multi: provide Curl_multiuse_state to update information

As soon as a TLS backend gets ALPN conformation about the specific HTTP
version it can now set the multiplex situation for the "bundle" and
trigger moving potentially queued up transfers to the CONNECT state.

lib/vtls/openssl.c

@@ -48,6 +48,7 @@
 #include "vtls.h"
 #include "strcase.h"
 #include "hostcheck.h"
+#include "multiif.h"
 #include "curl_printf.h"
 #include <openssl/ssl.h>
 #include <openssl/rand.h>
@@ -2917,6 +2918,9 @@ static CURLcode ossl_connect_step2(struct connectdata *conn, int sockindex)
       }
       else
         infof(data, "ALPN, server did not agree to a protocol\n");
+
+      Curl_multiuse_state(conn, conn->negnpn == CURL_HTTP_VERSION_2 ?
+                          BUNDLE_MULTIPLEX : BUNDLE_NO_MULTIUSE);
     }
 #endif