Broken backwards compatibility for account usage and limits
Motivation
----------
Due to the change from simple limits/usage to local/global usage and limits, the backwards compatibility for old clients is currently broken. This is due to the fact that the REST endpoints where changed from
```
    '/(.+)/limits', 'AccountLimits',
    '/(.+)/limits/(.+)', 'AccountLimits',
    '/(.+)/usage/', 'Usage1',
    '/(.+)/usage/(.+)', 'Usage2',
```
to
```
    '/(.+)/limits/local', 'LocalAccountLimits',
    '/(.+)/limits/local/(.+)', 'LocalAccountLimits',
    '/(.+)/limits/global', 'GlobalAccountLimits',
    '/(.+)/limits/global/(.+)', 'GlobalAccountLimits',
```
thus the required endpoints are missing for old clients. 

Modification
------------
The endpoints need to be re-added and pointing to the local version of the usage/limit.

diff --git a/lib/rucio/web/rest/webpy/v1/account.py b/lib/rucio/web/rest/webpy/v1/account.py
index e97acbdd4..5f41f2778 100755
--- a/lib/rucio/web/rest/webpy/v1/account.py
+++ b/lib/rucio/web/rest/webpy/v1/account.py
@@ -61,12 +61,16 @@ URLS = (
     '/(.+)/limits/local/(.+)', 'LocalAccountLimits',
     '/(.+)/limits/global', 'GlobalAccountLimits',
     '/(.+)/limits/global/(.+)', 'GlobalAccountLimits',
+    '/(.+)/limits', 'LocalAccountLimits',
+    '/(.+)/limits/(.+)', 'LocalAccountLimits',
     '/(.+)/rules', 'Rules',
     '/(.+)/usage/history/(.+)', 'UsageHistory',
     '/(.+)/usage/local', 'LocalUsage',
     '/(.+)/usage/local/(.+)', 'LocalUsage',
     '/(.+)/usage/global', 'GlobalUsage',
     '/(.+)/usage/global/(.+)', 'GlobalUsage',
+    '/(.+)/usage', 'LocalUsage',
+    '/(.+)/usage/(.+)', 'LocalUsage',
     '/(.+)', 'AccountParameter',
     '/?$', 'Account',
 )
['lib/rucio/web/rest/webpy/v1/account.py']