Build: move translations from install/po/ to top-level po/

Translations are need for client as well. This move is done to remove
dependency between client and install subdirectories.

https://fedorahosted.org/freeipa/ticket/6418

Reviewed-By: Lukas Slebodnik <lslebodn@redhat.com>
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

configure.ac

@@ -368,11 +368,11 @@ AC_CONFIG_FILES([
     install/tools/Makefile
     install/tools/man/Makefile
     install/updates/Makefile
-    install/po/Makefile
     install/restart_scripts/Makefile
     install/wsgi/Makefile
     install/oddjob/Makefile
     ipatests/man/Makefile
+    po/Makefile
     util/Makefile
 ])