修复kirk app host不能配置bug

Author: pqx

qiniu/services/compute/app.py

@@ -36,7 +36,7 @@ def __init__(self, auth, host=None):
         if (auth is None):
             self.host = KIRK_HOST['APPPROXY']
         else:
-            self.host = KIRK_HOST['APPGLOBAL']
+            self.host = host or KIRK_HOST['APPGLOBAL']
         acc, info = self.get_account_info()
         self.uri = acc.get('name')