git-svn: avoid respewing similar error messages for missing paths
We ignore errors if the path we're tracking did not exist for a particular revision range, but we still print out warnings telling the user about that.
As pointed out by Seth Falcon, this amounts to a lot of warnings that could confuse and worry users. I'm not entirely comfortable completely silencing the warnings, but showing one warning per path that we track should be reasonable.
Signed-off-by: Eric Wong <firstname.lastname@example.org> Signed-off-by: Junio C Hamano <email@example.com>