MINOR: frontend: add client timeout sample fetch

Add a sample fetch named fe_client_timeout to return the configuration
value for the client timeout on a frontend.
diff --git a/src/frontend.c b/src/frontend.c
index 3da48f2..5252711 100644
--- a/src/frontend.c
+++ b/src/frontend.c
@@ -254,17 +254,27 @@
 	return 1;
 }
 
+static int
+smp_fetch_fe_client_timeout(const struct arg *args, struct sample *smp, const char *km, void *private)
+{
+	smp->flags = SMP_F_VOL_TXN;
+	smp->data.type = SMP_T_SINT;
+	smp->data.u.sint = TICKS_TO_MS(smp->sess->fe->timeout.client);
+	return 1;
+}
+
 
 /* Note: must not be declared <const> as its list will be overwritten.
  * Please take care of keeping this list alphabetically sorted.
  */
 static struct sample_fetch_kw_list smp_kws = {ILH, {
-	{ "fe_conn",      smp_fetch_fe_conn,      ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
-	{ "fe_defbe",     smp_fetch_fe_defbe,     0,          NULL, SMP_T_STR,  SMP_USE_FTEND, },
-	{ "fe_id",        smp_fetch_fe_id,        0,          NULL, SMP_T_SINT, SMP_USE_FTEND, },
-	{ "fe_name",      smp_fetch_fe_name,      0,          NULL, SMP_T_STR,  SMP_USE_FTEND, },
-	{ "fe_req_rate",  smp_fetch_fe_req_rate,  ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
-	{ "fe_sess_rate", smp_fetch_fe_sess_rate, ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
+	{ "fe_client_timeout", smp_fetch_fe_client_timeout, 0,          NULL, SMP_T_SINT, SMP_USE_FTEND, },
+	{ "fe_conn",           smp_fetch_fe_conn,           ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
+	{ "fe_defbe",          smp_fetch_fe_defbe,          0,          NULL, SMP_T_STR,  SMP_USE_FTEND, },
+	{ "fe_id",             smp_fetch_fe_id,             0,          NULL, SMP_T_SINT, SMP_USE_FTEND, },
+	{ "fe_name",           smp_fetch_fe_name,           0,          NULL, SMP_T_STR,  SMP_USE_FTEND, },
+	{ "fe_req_rate",       smp_fetch_fe_req_rate,       ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
+	{ "fe_sess_rate",      smp_fetch_fe_sess_rate,      ARG1(1,FE), NULL, SMP_T_SINT, SMP_USE_INTRN, },
 	{ /* END */ },
 }};