[meta-oe] Fix bug with multilib in SRC_URI

SRC_URI is wrong when you try to compile with multilib using bitbake lib32-opensplice. The URI become :
ftp://ftp.openldap.org/pub/OpenLDAP/openldap-release/lib32-openldap-2.4.23.tgz
instead of :
ftp://ftp.openldap.org/pub/OpenLDAP/openldap-release/openldap-2.4.23.tgz