[IMPR] Remove _replace_sync_callback in replace.py
[IMPR] Remove _replace_sync_callback in replace.py

There is no reason to have a callback function for synchroneous
page save which in result does just nothing except preventing
showing the page save message and does a bulk save message
every 50 titles. Use the default Bot behaviour instead.

Change-Id: Icf4fa26727207aa7d52818be019055c0a42acf89

wikimedia/pywikibot-core,wikimedia/pywikibot-core