prserv: fix import of sqlite3

* this is used in all other bitbake parts where sqlite3 is used, don't
  know why it wasn't used here, but it fails e.g. on Gentoo
  Traceback (most recent call last):
    File "bin/bitbake", line 39, in <module>
      from bb import cooker
    File "lib/bb/cooker.py", line 39, in <module>
      import prserv.serv
    File "lib/prserv/serv.py", line 4, in <module>
      import xmlrpclib,sqlite3
  ImportError: No module named sqlite3

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

lib/prserv/serv.py

@@ -1,7 +1,12 @@
 import os,sys,logging
 import signal, time, atexit, threading
 from SimpleXMLRPCServer import SimpleXMLRPCServer, SimpleXMLRPCRequestHandler
-import xmlrpclib,sqlite3
+import xmlrpclib
+
+try:
+    import sqlite3
+except ImportError:
+    from pysqlite2 import dbapi2 as sqlite3
 
 import bb.server.xmlrpc
 import prserv