do not require name to create an account

gui/qt/main_window.py

@@ -1822,7 +1822,6 @@ class ElectrumWindow(QMainWindow):
         if not r: return
 
         name = str(e.text())
-        if not name: return
 
         self.wallet.create_pending_account(name, password)
         self.update_address_tab()

lib/wallet.py

@@ -1431,6 +1431,7 @@ class BIP32_HD_Wallet(BIP32_Wallet):
             self.next_account = self.get_next_account(password)
             self.storage.put('next_account', self.next_account)
         next_id, next_xpub, next_address = self.next_account
+        if name:
             self.set_label(next_id, name)
         self.accounts[next_id] = PendingAccount({'pending':next_address})
         self.save_accounts()