Land rapid7#8110, process migration by name fix

Author: wvu

modules/post/windows/manage/migrate.rb

@@ -42,7 +42,7 @@ def run
     if datastore['SPAWN']
       print_status("Spawning notepad.exe process to migrate to")
       target_pid = create_temp_proc
-    elsif datastore['PID'] != 0
+    elsif datastore['PID']
       target_pid = datastore['PID']
     elsif datastore['NAME']
       target_pid = session.sys.process[datastore['NAME']]