Prefer filterexpr if there is no title in config

Use 'Yet another column' only if there is no title and filterexpr is
also empty. This behavior is in accordance with change introduced in
fc154914.

topydo/ui/columns/ColumnLayout.py

@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import configparser
+from configparser import RawConfigParser, NoOptionError
 from os.path import expanduser
 
 from topydo.lib.Config import home_config_path, config
@@ -27,8 +27,15 @@ def columns(p_alt_layout_path=None):
     def _get_column_dict(p_cp, p_column):
         column_dict = dict()
 
-        column_dict['title'] = p_cp.get(p_column, 'title')
-        column_dict['filterexpr'] = p_cp.get(p_column, 'filterexpr')
+        filterexpr = p_cp.get(p_column, 'filterexpr')
+
+        try:
+            title = p_cp.get(p_column, 'title')
+        except NoOptionError:
+            title = filterexpr
+
+        column_dict['title'] = title or 'Yet another column'
+        column_dict['filterexpr'] = filterexpr
         column_dict['sortexpr'] = p_cp.get(p_column, 'sortexpr')
         column_dict['groupexpr'] = p_cp.get(p_column, 'groupexpr')
         column_dict['show_all'] = p_cp.getboolean(p_column, 'show_all')
@@ -36,14 +43,13 @@ def columns(p_alt_layout_path=None):
         return column_dict
 
     defaults = {
-            'title':  'Yet another column',
             'filterexpr': '',
             'sortexpr': config().sort_string(),
             'groupexpr': config().group_string(),
             'show_all': '0',
     }
 
-    cp = configparser.RawConfigParser(defaults)
+    cp = RawConfigParser(defaults)
     files = [
         "topydo_columns.ini",
         "topydo_columns.conf",