gitpython-developers#1566 Creating a lock now uses python built-in "o…

…pen()" method to work around docker virtiofs issue (backport to 1.0.2)

git/util.py

@@ -539,8 +539,7 @@ def _obtain_lock_or_raise(self):
                           (self._file_path, lock_file))
 
         try:
-            fd = os.open(lock_file, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0)
-            os.close(fd)
+            open(lock_file, mode='w', closefd=True)
         except OSError as e:
             raise IOError(str(e))