Merge pull request #1663 from tim-moody/map-dirs

handle first time when idx file does not exist

roles/osm-vector-maps/templates/iiab-update-map

@@ -114,9 +114,12 @@ def get_installed_regions():
 
 def read_vector_map_idx():
    global previous_idx
+   try: # will fail first time
       with open(vector_map_idx_dir + '/vector-map-idx.json','r') as idx:
          str = idx.read()
          previous_idx = json.loads(str)
+   except:
+      pass
 
 def write_vector_map_idx(installed_maps):
    map_dict ={}