PushSafer: Handle empty data section properly (home-assistant#154109)

Author: LennartC

homeassistant/components/pushsafer/notify.py

@@ -88,7 +88,7 @@ def send_message(self, message="", **kwargs):
             _LOGGER.debug("%s target(s) specified", len(targets))
 
         title = kwargs.get(ATTR_TITLE, ATTR_TITLE_DEFAULT)
-        data = kwargs.get(ATTR_DATA, {})
+        data = kwargs.get(ATTR_DATA) or {}
 
         # Converting the specified image to base64
         picture1 = data.get(ATTR_PICTURE1)