Fix missing/extra imports

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/accounts/management/commands/dumpuserdata.py

@@ -18,6 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+import argparse
 import json
 
 from django.core.management.base import BaseCommand

weblate/accounts/management/commands/importuserdata.py

@@ -18,6 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+import argparse
 import json
 
 from django.core.management.base import BaseCommand

weblate/lang/management/commands/checklang.py

@@ -18,7 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-from django.core.management.base import BaseCommand, CommandError
+from django.core.management.base import BaseCommand
 from weblate.lang.models import Language