io MAINTENANCE init variable

just shut up compiler
diff --git a/src/io.c b/src/io.c
index fd21951..7aa31ef 100644
--- a/src/io.c
+++ b/src/io.c
@@ -923,7 +923,7 @@
     struct wclb_arg arg;
     const char **capabilities;
     uint32_t *sid = NULL, i;
-    int wd;
+    int wd = 0;
 
     assert(session);