MEDIUM: connections: Don't reset the polling flags in conn_fd_handler().

Resetting the polling flags at the end of conn_fd_handler() shouldn't be
needed anymore, and it will create problem when we won't handle send/recv
from conn_fd_handler() anymore.
diff --git a/src/connection.c b/src/connection.c
index ab32567..e303f2c 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -203,9 +203,6 @@
 	    conn->mux->wake(conn) < 0)
 		return;
 
-	/* remove the events before leaving */
-	fdtab[fd].ev &= FD_POLL_STICKY;
-
 	/* commit polling changes */
 	conn->flags &= ~CO_FL_WILL_UPDATE;
 	conn_cond_update_polling(conn);