Fixes #3791 cron always returning changed state for multiline jobs (#4285)

Strip only newlines and carriage returns. Instead of stripping ALL whitespace, which may have unintended side effects

lib/ansible/modules/system/cron.py

@@ -383,6 +383,9 @@ class CronTab(object):
         return []
 
     def get_cron_job(self,minute,hour,day,month,weekday,job,special,disabled):
+        # normalize any leading/trailing newlines (ansible/ansible-modules-core#3791)
+        job = job.strip('\r\n')
+
         if disabled:
             disable_prefix = '#'
         else: