Don't print unnecessary backtraces when testing

When stg fails, and handles it properly, no backtrace should be printed, even when running tests with -v. Getting a backtrace in the output signals some kind of bug, but in this case there is no bug.
---

I was running tests with -v and saw python backtraces, and assumed that there was a bug somewhere. But apparently this backtrace only appeared when running tests.

I think it's better if you only get backtraces when something actually went wrong. The test driver sets the debug level to -1, so I changed the check to check for positive instead.

 stgit/main.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

index 294b703..2390110 100644
@@ -286,7 +286,7 @@ def main():
             StackException, GitException, GitMergeException,
             EditorException), err:
         print >> sys.stderr, '%s %s: %s' % (prog, cmd, err)
-        if debug_level:
+        if debug_level > 0:
             raise
         else:
             sys.exit(2)

1.5.3.rc3.119.g1812


-- 
David Kågedal