LWM2M: Fix a NULL pointer deference.

After setting client->bootstrap_ctx.server_uri to NULL, a SOL_WRN() statement
was trying to print the contents of client->bootstrap_ctx.server_uri.

Signed-off-by: Guilherme Iscaro <[email protected]>

Author: cabelitos

src/lib/comms/sol-lwm2m.c

@@ -4621,8 +4621,6 @@ client_bootstrap(void *data)
     conn_ctx = server_connection_ctx_new(client,
         sol_str_slice_from_blob(client->bootstrap_ctx.server_uri),
         DEFAULT_SHORT_SERVER_ID);
-    sol_blob_unref(client->bootstrap_ctx.server_uri);
-    client->bootstrap_ctx.server_uri = NULL;
 
     if (!conn_ctx) {
         SOL_WRN("Could not perform Client-initiated Bootstrap with server %.*s",
@@ -4636,6 +4634,9 @@ client_bootstrap(void *data)
             SOL_WRN("Could not unregister Bootstrap Finish resource for client.");
     }
 
+    sol_blob_unref(client->bootstrap_ctx.server_uri);
+    client->bootstrap_ctx.server_uri = NULL;
+
     return false;
 }