[damned-lies] fix: ensure django.po exists before extracting code str

[Guillaume Bernard <gbernard src gnome org>]

commit 718e046b6c854c439f249077bff4772dae5d6dd5
Author: Guillaume Bernard <associations guillaume-bernard fr>
Date:   Fri Jul 9 19:54:35 2021 +0200

    fix: ensure django.po exists before extracting code str

 stats/management/commands/update-trans.py | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/stats/management/commands/update-trans.py b/stats/management/commands/update-trans.py
index 643fde57..c1d1d729 100644
--- a/stats/management/commands/update-trans.py
+++ b/stats/management/commands/update-trans.py
@@ -33,11 +33,13 @@ class Command(BaseCommand):
             self._update_django_po_with_code_strings()
 
             # backup code-only strings in the code.po file. Remove non code related msgid (mainly coming 
from database)
-            code_po_file = str(self.locale_dir / "code.po")
-            shutil.copy(str(self.locale_dir / "django.po"), code_po_file)
-            subprocess.run(
-                ["/usr/bin/msgattrib", "--no-obsolete", "-o", str(code_po_file), str(code_po_file)], 
check=True
-            )
+            django_po_file = self.locale_dir / "django.po"
+            if django_po_file.is_file():
+                code_po_file = self.locale_dir / "code.po"
+                shutil.copy(django_po_file, code_po_file)
+                subprocess.run(
+                    ["/usr/bin/msgattrib", "--no-obsolete", "-o", str(code_po_file), str(code_po_file)], 
check=True
+                )
 
         self._update_django_po_with_database_strings()