BUG/MINOR: h3: fix crash due to h3 traces

First H3 traces argument must be a connection instance or a NULL. Some
new traces were added recently with a qcc instance which caused a crash
when traces are activated.

This trace was added by the following patch :
    87f8766d3fbd10f9e8bf4902d37712612db64df5
    BUG/MEDIUM: h3: handle STOP_SENDING on control stream

This must be backported up to 2.6 along with the above patch.
1 file changed