Use restart_callback in all situations

Fixes #438
Prior to this commit, if Load Wallet were selected
from the menu and a wallet loaded did not have imports,
the restart prompt message appeared only on the console
and the application quit via sys.exit().
After this commit, the Qt restart callback is always used,
as intended. The case of recovery sync for old, heavily
used wallets is not covered.

scripts/joinmarket-qt.py

@@ -1509,9 +1509,9 @@ class JMMainWindow(QMainWindow):
 
         JMQtMessageBox(self, 'Wallet saved to ' + self.walletname,
                                    title="Wallet created")
-        self.initWallet(seed=self.walletname, restart_cb=self.restartWithMsg)
+        self.initWallet(seed=self.walletname)
 
-    def selectWallet(self, testnet_seed=None, restart_cb=None):
+    def selectWallet(self, testnet_seed=None):
         if jm_single().config.get("BLOCKCHAIN", "blockchain_source") != "regtest":
             current_path = os.path.dirname(os.path.realpath(__file__))
             if os.path.isdir(os.path.join(current_path, 'wallets')):
@@ -1533,7 +1533,7 @@ class JMMainWindow(QMainWindow):
                 if not ok:
                     return
                 pwd = str(text).strip()
-                decrypted = self.loadWalletFromBlockchain(firstarg[0], pwd, restart_cb)
+                decrypted = self.loadWalletFromBlockchain(firstarg[0], pwd)
         else:
             if not testnet_seed:
                 testnet_seed, ok = QInputDialog.getText(self,
@@ -1545,9 +1545,9 @@ class JMMainWindow(QMainWindow):
             firstarg = str(testnet_seed)
             pwd = None
             #ignore return value as there is no decryption failure possible
-            self.loadWalletFromBlockchain(firstarg, pwd, restart_cb)
+            self.loadWalletFromBlockchain(firstarg, pwd)
 
-    def loadWalletFromBlockchain(self, firstarg=None, pwd=None, restart_cb=None):
+    def loadWalletFromBlockchain(self, firstarg=None, pwd=None):
         if firstarg:
             wallet_path = get_wallet_path(str(firstarg), None)
             try:
@@ -1575,7 +1575,7 @@ class JMMainWindow(QMainWindow):
             self.walletRefresh.stop()
 
         self.wallet_service = WalletService(wallet)
-        self.wallet_service.add_restart_callback(restart_cb)
+        self.wallet_service.add_restart_callback(self.restartWithMsg)
         self.wallet_service.startService()
         self.walletRefresh = task.LoopingCall(self.updateWalletInfo)
         self.walletRefresh.start(5.0)
@@ -1600,7 +1600,7 @@ class JMMainWindow(QMainWindow):
             seed = self.getTestnetSeed()
             self.selectWallet(testnet_seed=seed)
         else:
-            self.initWallet(restart_cb=self.restartWithMsg)
+            self.initWallet()
 
     def getTestnetSeed(self):
         text, ok = QInputDialog.getText(
@@ -1692,7 +1692,7 @@ class JMMainWindow(QMainWindow):
             return None
         return str(mnemonic_extension)
 
-    def initWallet(self, seed=None, restart_cb=None):
+    def initWallet(self, seed=None):
         '''Creates a new wallet if seed not provided.
         Initializes by syncing.
         '''
@@ -1717,8 +1717,7 @@ class JMMainWindow(QMainWindow):
 
             JMQtMessageBox(self, 'Wallet saved to ' + self.walletname,
                            title="Wallet created")
-        self.loadWalletFromBlockchain(self.walletname, pwd=self.textpassword,
+        self.loadWalletFromBlockchain(self.walletname, pwd=self.textpassword)
-                                      restart_cb=restart_cb)
 
 def get_wallet_printout(wallet_service):
     """Given a WalletService object, retrieve the list of