rpc: rename getdeploymentinfo status-next to status_next

test/functional/rpc_blockchain.py

@@ -200,7 +200,7 @@ class BlockchainTest(BitcoinTestFramework):
                     'timeout': 0x7fffffffffffffff,  # testdummy does not have a timeout so is set to the max int64 value
                     'min_activation_height': 0,
                     'status': 'started',
-                    'status-next': status_next,
+                    'status_next': status_next,
                     'since': 144,
                     'statistics': {
                         'period': 144,
@@ -220,7 +220,7 @@ class BlockchainTest(BitcoinTestFramework):
                     'timeout': 9223372036854775807,
                     'min_activation_height': 0,
                     'status': 'active',
-                    'status-next': 'active',
+                    'status_next': 'active',
                     'since': 0,
                 },
                 'height': 0,