Be consistent in enable state: use human readable values

weboob/tools/application/qt/backendcfg.py

@@ -239,14 +239,14 @@ class BackendCfg(QDialog):
         bname = unicode(item.text(1))
         if item.checkState(0) == Qt.Checked:
             self.to_load.add(instname)
-            enabled = '1'
+            enabled = 'true'
         else:
             self.to_unload.add(instname)
             try:
                 self.to_load.remove(instname)
             except KeyError:
                 pass
-            enabled = '0'
+            enabled = 'false'
 
         self.weboob.backends_config.edit_backend(instname, bname, {'_enabled': enabled})