Auto merge of zcash#1918 - bitcartel:timeout_cpu_throttling, r=str4d

Increase timeout as laptops on battery power have cpu throttling.

Merge this last as other PRs also update the test file `wallet_protectcoinbase.py`.

qa/rpc-tests/wallet_protectcoinbase.py

@@ -28,7 +28,7 @@ def wait_and_assert_operationid_status(self, myopid, in_status='success', in_err
         print('waiting for async operation {}'.format(myopid))
         opids = []
         opids.append(myopid)
-        timeout = 120
+        timeout = 300
         status = None
         errormsg = None
         txid = None