session CHANGE support for old compilers without C11 atomic
diff --git a/src/session_server.c b/src/session_server.c
index 761cff8..ed38f48 100644
--- a/src/session_server.c
+++ b/src/session_server.c
@@ -673,7 +673,7 @@
     (*session)->ctx = server_opts.ctx;
 
     /* assign new SID atomically */
-    (*session)->id = atomic_fetch_add(&server_opts.new_session_id, 1);
+    (*session)->id = ATOMIC_INC(&server_opts.new_session_id);
 
     /* NETCONF handshake */
     msgtype = nc_handshake_io(*session);
@@ -1982,7 +1982,7 @@
     pthread_rwlock_unlock(&server_opts.endpt_lock);
 
     /* assign new SID atomically */
-    (*session)->id = atomic_fetch_add(&server_opts.new_session_id, 1);
+    (*session)->id = ATOMIC_INC(&server_opts.new_session_id);
 
     /* NETCONF handshake */
     msgtype = nc_handshake_io(*session);
@@ -2044,7 +2044,7 @@
         return -1;
     }
     server_opts.ch_clients[server_opts.ch_client_count - 1].name = lydict_insert(server_opts.ctx, name, 0);
-    server_opts.ch_clients[server_opts.ch_client_count - 1].id = atomic_fetch_add(&server_opts.new_client_id, 1);
+    server_opts.ch_clients[server_opts.ch_client_count - 1].id = ATOMIC_INC(&server_opts.new_client_id);
     server_opts.ch_clients[server_opts.ch_client_count - 1].ti = ti;
     server_opts.ch_clients[server_opts.ch_client_count - 1].ch_endpts = NULL;
     server_opts.ch_clients[server_opts.ch_client_count - 1].ch_endpt_count = 0;
@@ -2722,7 +2722,7 @@
     }
 
     /* assign new SID atomically */
-    (*session)->id = atomic_fetch_add(&server_opts.new_session_id, 1);
+    (*session)->id = ATOMIC_INC(&server_opts.new_session_id);
 
     /* NETCONF handshake */
     msgtype = nc_handshake_io(*session);