libnm: add NMIPAddress and NMIPRoute dups backported symbols from 1.30.8
The nm_ip_address_dup() and nm_ip_route_dup() symbols were exposed in libnm 1.32 and then backported to 1.30.8.
Export it also with version @libnm_1_30_8; this allows a program build against libnm 1.30.8 to keep working with later versions of the library.
Signed-off-by: Fernando Fernandez Mancera ffmancera@riseup.net (cherry picked from commit ec8df200)