Max sure max headroom variable is 64 bit

src/stratifier.c

@@ -2456,10 +2456,10 @@ static sdata_t *select_sdata(const ckpool_t *ckp, sdata_t *ckp_sdata)
 
 	mutex_lock(&ckp_sdata->proxy_lock);
 	HASH_ITER(hh, ckp_sdata->proxies, proxy, tmp) {
-		int most_headroom;
+		int64_t max_headroom;
 
 		best = NULL;
-		proxy->headroom = most_headroom = 0;
+		proxy->headroom = max_headroom = 0;
 		HASH_ITER(sh, proxy->subproxies, subproxy, tmpsub) {
 			int64_t subproxy_headroom;
 
@@ -2470,9 +2470,9 @@ static sdata_t *select_sdata(const ckpool_t *ckp, sdata_t *ckp_sdata)
 			subproxy_headroom = subproxy->max_clients - subproxy->clients;
 
 			proxy->headroom += subproxy_headroom;
-			if (subproxy_headroom > most_headroom) {
+			if (subproxy_headroom > max_headroom) {
 				best = subproxy;
-				most_headroom = subproxy_headroom;
+				max_headroom = subproxy_headroom;
 			}
 		}
 		if (best && best->id < best_id) {