Add client certificate support

src/client/etcd_state_client.h

@@ -124,7 +124,10 @@ public:
     uint32_t global_bitmap_granularity = DEFAULT_BITMAP_GRANULARITY;
     uint32_t global_immediate_commit = IMMEDIATE_NONE;
 
+    uint64_t osd_num = 0;
     std::string etcd_prefix;
+    std::string etcd_client_cert;
+    std::string etcd_client_key;
     std::string etcd_ca;
     int log_level = 0;
     timerfd_manager_t *tfd = NULL;