Namecoin: Fix broadcast() usage

Upstream Electrum changed the return value of broadcast().  Previously,
errors would be encoded in the return value.  Now errors are raised as
exceptions, and the return value is just a txid.  This commit fixes our
usage accordingly.

electrum_nmc/commands.py

@@ -681,9 +681,10 @@ def name_autoregister(self, identifier, value, destination=None, amount=0.0, fee
         new_rand = new_result["rand"]
         new_tx = new_result["tx"]["hex"]
 
-        status, msg = self.broadcast(new_tx)
-        if not status:
-            raise Exception("Error broadcasting name pre-registration: " + msg)
+        try:
+            self.broadcast(new_tx)
+        except Exception as e:
+            raise Exception("Error broadcasting name pre-registration: " + str(e))
 
         # We add the name_new transaction to the wallet explicitly because
         # otherwise, the wallet will only learn about the name_new once the
@@ -931,9 +932,10 @@ def updatequeuedtransactions(self):
 
             if current_depth >= trigger_depth:
                 tx = queue_item["tx"]
-                status, msg = self.broadcast(tx)
-                if not status:
-                    errors[txid] = msg
+                try:
+                    self.broadcast(tx)
+                except Exception as e:
+                    errors[txid] = str(e)
 
                 to_unqueue.append(txid)
 

electrum_nmc/gui/qt/configure_name_dialog.py

@@ -149,10 +149,11 @@ def update_and_broadcast(self, identifier, value, transfer_to):
         # TODO: support non-ASCII encodings
         tx = name_update(identifier.decode('ascii'), value.decode('ascii'), recipient_address)['hex']
 
-        status, msg = broadcast(tx)
-        if not status:
+        try:
+            broadcast(tx)
+        except Exception as e:
             formatted_name = format_name_identifier(identifier)
-            self.main_window.show_error(_("Error broadcasting update for ") + formatted_name + ": " + str(msg))
+            self.main_window.show_error(_("Error broadcasting update for ") + formatted_name + ": " + str(e))
             return
 
         # As far as I can tell, we don't need to explicitly add the transaction

electrum_nmc/gui/qt/uno_list.py

@@ -127,10 +127,11 @@ def renew_selected_items(self):
                 # The name was recently updated, so skip it and don't renew.
                 continue
 
-            status, msg = broadcast(tx)
-            if not status:
+            try:
+                broadcast(tx)
+            except Exception as e:
                 formatted_name = format_name_identifier(identifier)
-                self.parent.show_error(_("Error broadcasting renewal for ") + formatted_name + ": " + str(msg))
+                self.parent.show_error(_("Error broadcasting renewal for ") + formatted_name + ": " + str(e))
                 continue
 
             # We add the transaction to the wallet explicitly because