CONTRIB: debug: fix build related to conn_stream flags change

Commit 53216e7db ("MEDIUM: connections: Don't directly mess with the
polling from the upper layers.") removed the CS_FL_DATA_RD_ENA and
CS_FL_DATA_WR_ENA flags without updating flags.c, thus breaking the
build. This patch also adds flag CL_FL_NOT_FIRST which was brought
by commit 08088e77c.
1 file changed