json/rpc: Fix. Support not fully implemented subsystems.

Change-Id: I3cbc052dd4732a48c0d182b90e0c1b12a2f218c6
Signed-off-by: Pawel Kaminski <pawelx.kaminski@intel.com>
Reviewed-on: https://review.gerrithub.io/406317
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

scripts/rpc/__init__.py

@@ -59,4 +59,6 @@ def load_config(client, args):
         if not config:
             continue
         for elem in subsystem['config']:
+            if not elem or 'method' not in config:
+                continue
             client.call(elem['method'], elem['params'])