chore(bunny): add comments on logging (#483)

Signed-off-by: Arjun Rajappa <Arjun.Rajappa@ibm.com>

Author: arjun-rajappa

lib/instana/instrumentation/bunny.rb

@@ -121,6 +121,7 @@ def extract_context_from_headers(properties)
       end
 
       def log_error(error)
+        # Log errors on to console if INSTANA_DEBUG is enabled
         ::Instana.logger.debug { "#{__method__}:#{File.basename(__FILE__)}:#{__LINE__}: #{error.message}" }
       end
     end