MINOR: threads: Add nbthread parameter

It is only parsed and initialized for now. It will be used later. This parameter
is only available when support for threads was built in.
diff --git a/src/haproxy.c b/src/haproxy.c
index a4e62a7..bd8dfd6 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -77,6 +77,7 @@
 #include <common/time.h>
 #include <common/uri_auth.h>
 #include <common/version.h>
+#include <common/hathreads.h>
 
 #include <types/capture.h>
 #include <types/filters.h>
@@ -122,6 +123,7 @@
 struct global global = {
 	.hard_stop_after = TICK_ETERNITY,
 	.nbproc = 1,
+	.nbthread = 1,
 	.req_count = 0,
 	.logsrvs = LIST_HEAD_INIT(global.logsrvs),
 	.maxzlibmem = 0,
@@ -1754,6 +1756,9 @@
 	if (global.nbproc < 1)
 		global.nbproc = 1;
 
+	if (global.nbthread < 1)
+		global.nbthread = 1;
+
 	/* Realloc trash buffers because global.tune.bufsize may have changed */
 	if (!init_trash_buffers()) {
 		Alert("failed to initialize trash buffers.\n");