Don't use both AM_GNU_GETTEXT and IT_PROG_INTLTOOL

When using IT_PROG_INTLTOOL, AM_GNU_GETTEXT and related macros
are not necessary. Newer version of automake fails because both
macros try to generate po/Makefile.in.in.
Fix typo in error logging in Twisted callback

self.log.err is undefined, should have read simply log.err