Remove the incorrect bug tracker link

Current Bug tracker link mentioned in README file does not exit which
create confusion. I checked and not found any bug tracker for this project.
Removing the incorrect link and mention to raise bug on ML or IRC.

Change-Id: Ifd9375cf09154b4439f2c75ff42103535d271270

README.rst

@@ -8,7 +8,7 @@ Python scripts for use in OpenStack's Performance Measurement
 * Free software: Apache license
 * Documentation: http://docs.openstack.org/developer/os-performance-tools
 * Source: http://opendev.org/openstack/os-performance-tools
-* Bugs: http://bugs.launchpad.net/openstack-qa
+* Bugs: No bug tracker as of now, report on ML or IRC #openstack-qa channel.
 
 Features
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