Improve huobi config generation

freqtrade/templates/subtemplates/exchange_huobi.j2

@@ -0,0 +1,12 @@
+"exchange": {
+    "name": "{{ exchange_name | lower }}",
+    "key": "{{ exchange_key }}",
+    "secret": "{{ exchange_secret }}",
+    "ccxt_config": {},
+    "ccxt_async_config": {},
+    "pair_whitelist": [
+    ],
+    "pair_blacklist": [
+        "HT/.*"
+    ]
+}