JSONLoadError even when JSON config being loaded in proper
```python
    cnf = """{
        "configuration" : {
            "system" : {
                "services" : {
                    "telnet" : [null]
                 }
            }
        }
    }"""
    with Config(dev) as cu:
        cu.load(cnf, format='json')
```
throw JSONLoadError even when JSON config being loaded in proper
This issue got introduced after the changes done for enhancement under https://github.com/Juniper/py-junos-eznc/pull/706


diff --git a/lib/jnpr/junos/device.py b/lib/jnpr/junos/device.py
index dd1758a8..9d392e44 100644
--- a/lib/jnpr/junos/device.py
+++ b/lib/jnpr/junos/device.py
@@ -736,8 +736,11 @@ class _Connection(object):
 
         # From 14.2 onward, junos supports JSON, so now code can be written as
         # dev.rpc.get_route_engine_information({'format': 'json'})
+        # should not convert rpc response to json when loading json config
+        # as response should be rpc-reply xml object.
 
-        if rpc_cmd_e.attrib.get('format') in ['json', 'JSON']:
+        if rpc_cmd_e.tag != 'load-configuration' and \\
+                        rpc_cmd_e.attrib.get('format') in ['json', 'JSON']:
             ver_info = self.facts.get('version_info')
             if ver_info and ver_info.major[0] >= 15 or \\
                     (ver_info.major[0] == 14 and ver_info.major[1] >= 2):
['lib/jnpr/junos/device.py']