Update app.py

app.py

@@ -497,10 +497,10 @@ def mychain_mine_block_rec(balance, chain_r=None,chain_n=None):
 
 
 def issue_tokens(send,rec,amount):
-    response_send=None
-    response_rec=None
-    show_chain_send=None
-    show_chain_rec=None
+    response_send={}
+    response_rec={}
+    show_chain_send={}
+    show_chain_rec={}
     data_send=None
     data_rec=None
     message_send=None