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/sectransp.c

@@ -31,6 +31,7 @@
 #include "urldata.h" /* for the Curl_easy definition */
 #include "curl_base64.h"
 #include "strtok.h"
+#include "multiif.h"
 
 #ifdef USE_SECTRANSP
 
@@ -2651,6 +2652,9 @@ sectransp_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);
+
         /* chosenProtocol is a reference to the string within alpnArr
            and doesn't need to be freed separately */
         if(alpnArr)