bitcoin.NetworkConstants: easier changing between testnet and mainnet

plugins/trezor/plugin.py

@@ -9,7 +9,7 @@ from electrum.util import bfh, bh2u
 from electrum.bitcoin import (is_segwit_address, b58_address_to_hash160, xpub_from_pubkey,
                               public_key_to_p2pkh, EncodeBase58Check,
                               TYPE_ADDRESS, TYPE_SCRIPT,
-                              TESTNET, ADDRTYPE_P2PKH, ADDRTYPE_P2SH)
+                              NetworkConstants)
 from electrum.i18n import _
 from electrum.plugins import BasePlugin, hook
 from electrum.transaction import deserialize, Transaction
@@ -142,7 +142,7 @@ class TrezorCompatiblePlugin(HW_PluginBase):
         return client
 
     def get_coin_name(self):
-        return "Testnet" if TESTNET else "Bitcoin"
+        return "Testnet" if NetworkConstants.TESTNET else "Bitcoin"
 
     def initialize_device(self, device_id, wizard, handler):
         # Initialization method