Fixes json parsing of None when no json was postesd to the API

h/t @yahgwai for finding this.

apps/cli/README.md

@@ -36,7 +36,7 @@ This command is used to register appointments to the PISA server. Appointments *
 	  "tx_id": tx_id,
 	  "start_time": s,
 	  "end_time": e,
-	  "dispute_delta": d }
+	  "to_self_delay": d }
 	
 `tx` **must** be the raw penalty transaction that will be encrypted before sent to the PISA server. `type(tx) = hex encoded str`
 

pisa/api.py

@@ -40,6 +40,7 @@ class API:
 
         logger.info("Received add_appointment request", from_addr_port="{}:{}".format(remote_addr, remote_port))
 
+        if request.is_json:
             # Check content type once if properly defined
             request_data = json.loads(request.get_json())
             inspector = Inspector(self.config)
@@ -70,6 +71,11 @@ class API:
                 rcode = HTTP_BAD_REQUEST
                 error = "appointment rejected. Request does not match the standard"
 
+        else:
+            rcode = HTTP_BAD_REQUEST
+            error = "appointment rejected. Request is not json encoded"
+            response = None
+
         logger.info(
             "Sending response and disconnecting",
             from_addr_port="{}:{}".format(remote_addr, remote_port),