[inferTraceBugs] fix crash on no-longer-needed bucket removal

Summary:
@public
utils.remove_bucket no longer exists and is no longer needed.

Test Plan:
  cd ~/infer/examples
  infer -- clang -c hello.c
  inferTraceBugs

no longer crashes

infer/bin/inferTraceBugs

@@ -52,7 +52,7 @@ def describe_report(report, indent=0):
     kind = report['kind']
     line = report['line']
     error_type = report['type']
-    msg = utils.remove_bucket(report['qualifier'])
+    msg = report['qualifier']
     return '{0}:{1}: {2}: {3}\n  {4}{5}\n'.format(
         filename,
         line,