ffpb: check that batcave_url is set

modules/ffpb.py

@@ -129,7 +129,11 @@ def setup(bot):
         msgserver_thread.start()
 
     # initialize BATCAVE
-    __batcave = BatcaveClient(bot.config.ffpb.batcave_url)
+    if bot.config.ffpb.batcave_url is None:
+        raise Exception("You did not specify [ffpb].batcave_url ...")
+    else:
+        print('using BATCAVE at ' + bot.config.ffpb.batcave_url)
+        __batcave = BatcaveClient(bot.config.ffpb.batcave_url)
 
     # signal end of setup routine
     bot.memory['ffpb_in_setup'] = False