Fixed db_migrator version 4_0_3 and 4_0_4 and added missing log info …

…to version 4_0_1 (sonic-net#2912)

#### What I did

In PR sonic-net#2893 the db_migrator "migrate_dns_nameserver" was misplaced in the latest version being version 4_0_4 instead of being placed in version 4_0_3. 

Additionally, the log info for version 4_0_1 was missing as well

scripts/db_migrator.py

@@ -1013,6 +1013,8 @@ def version_4_0_1(self):
  """
  Version 4_0_1.
  """
+ log.log_info('Handling version_4_0_1')
+
  self.migrate_feature_timer()
  self.set_version('version_4_0_2')
  return 'version_4_0_2'
@@ -1034,6 +1036,9 @@ def version_4_0_3(self):
  Version 4_0_3.
  """
  log.log_info('Handling version_4_0_3')
+
+ # Updating DNS nameserver
+ self.migrate_dns_nameserver()
  self.set_version('version_4_0_4')
  return 'version_4_0_4'
 
@@ -1043,8 +1048,6 @@ def version_4_0_4(self):
  This is the latest version for master branch
  """
  log.log_info('Handling version_4_0_4')
- # Updating DNS nameserver
- self.migrate_dns_nameserver()
  return None
 
  def get_version(self):