BUG/MEDIUM: promex: Be sure to never set EOM flag on an empty HTX message

It is the same bug than "BUG/MEDIUM: stats: Be sure to never set EOM flag on
an empty HTX message". We must be sure to set the EOM flag on a non empyt
message to be sure the mux on the client will properly handle
shutdowns. Otherwise, it may miss the end of the message and considers any
shutdown as an abort.

This patch must be backported as far as 2.4. On previous version there is
still the EOM HTX block.
1 file changed