CancelDeadlineTimer after doWrite

After doWrite we are no longer in a context where
the user can keep the connection open. Cancel the timer.

Tested: On a slow connection, still get responses

Change-Id: I75a5bb32ccaaae173bb37fe9717b3e63e85c7131
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/http/http_connection.h b/http/http_connection.h
index c413990..d3db78e 100644
--- a/http/http_connection.h
+++ b/http/http_connection.h
@@ -869,6 +869,8 @@
                 BMCWEB_LOG_DEBUG << this << " async_write " << bytes_transferred
                                  << " bytes";
 
+                cancelDeadlineTimer();
+
                 if (ec)
                 {
                     BMCWEB_LOG_DEBUG << this << " from write(2)";