[damned-lies] Removed unneeded GitRepo.exists override

[Claude Paroz <claudep src gnome org>]

commit fdca774a5cb29a6aee2dd95f5a44c8dffb4f7623
Author: Claude Paroz <claude 2xlibre net>
Date:   Sat Sep 18 14:34:50 2021 +0200

    Removed unneeded GitRepo.exists override

 stats/repos.py | 7 -------
 1 file changed, 7 deletions(-)
---
diff --git a/stats/repos.py b/stats/repos.py
index 094e2de7..1434b303 100644
--- a/stats/repos.py
+++ b/stats/repos.py
@@ -43,13 +43,6 @@ class RepoBase:
 
 
 class GitRepo(RepoBase):
-    def exists(self):
-        if not self.branch.co_path.exists():
-            return False
-        command = "git branch | grep %s" % self.branch.name
-        status, output, errs = run_shell_command(command, cwd=self.branch.co_path)
-        return output != ""
-
     def init_checkout(self):
         if self.branch.is_head():
             # We are assuming here that this is the first branch created