slaprunner resiliencytest fixup: check if old data is present in new data log

resiliency data in instance_root/slappart0/var/log/log.log is writen by a service in slaprunner, so after the takeover
the service will start again an write a new entry. We should then check if data from old runner0 is present in new data log.

slapos/resiliencytest/suites/slaprunner.py

@@ -279,7 +279,7 @@ class SlaprunnerTestSuite(ResiliencyTestSuite):
     time.sleep(15)
     new_data = self._retrieveInstanceLogFile()
 
-    if new_data == self.data:
+    if new_data.startswith(self.data):
       self.logger.info('Data are the same: success.')
       return True
     else: