Set paramserver snapshot flag when snapshot file not exist.

Author: hillbrook

ros/ros_comm/rosmaster/src/rosmaster/paramserver.py

@@ -70,11 +70,11 @@ def __init__(self, reg_manager):
 
         if "ROS_MASTER_SNAPSHOT" in os.environ:
             try:
+                self.snapshot = True
                 self.snapshot_file = os.path.join(os.environ["ROS_ROOT"], ".master_snapshot")
                 with open(self.snapshot_file, "r") as f:
                     self.parameters = json.loads(f.read())
                 del self.parameters["run_id"]
-                self.snapshot = True
             except IOError:
                 pass
             except KeyError: