[meld] Fix incorrect use of f-strings for i18n content

[Kai Willadsen <kaiw src gnome org>]

commit 0cd9b29320dd30e2f44eb183e0dfdc9934b92b36
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Mar 6 08:12:17 2021 +1000

    Fix incorrect use of f-strings for i18n content

 meld/dirdiff.py  | 3 ++-
 meld/filediff.py | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/meld/dirdiff.py b/meld/dirdiff.py
index 678659dc..6ba5acc5 100644
--- a/meld/dirdiff.py
+++ b/meld/dirdiff.py
@@ -947,7 +947,8 @@ class DirDiff(Gtk.VBox, tree.TreeviewCommon, MeldDoc):
     def _show_duplicate_directory(self, duplicate_directory):
         for index in range(self.num_panes):
             primary = _(
-                f'Folder {duplicate_directory} is being compared to itself')
+                'Folder {} is being compared to itself').format(
+                duplicate_directory)
             self.msgarea_mgr[index].add_dismissable_msg(
                 'dialog-warning-symbolic', primary, '', self.msgarea_mgr)
 
diff --git a/meld/filediff.py b/meld/filediff.py
index ba4a7813..e40f1293 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -1827,7 +1827,8 @@ class FileDiff(Gtk.VBox, MeldDoc):
         if duplicate_files:
             for index in range(self.num_panes):
                 primary = _(
-                    f'File {duplicate_files[0]} is being compared to itself')
+                    'File {} is being compared to itself').format(
+                    duplicate_files[0])
                 self.msgarea_mgr[index].add_dismissable_msg(
                     'dialog-warning-symbolic', primary, '', self.msgarea_mgr)
         elif self.linediffer.sequences_identical():