libfsoresource: (gdbus) fix catching errors when we can't get the proxy
libfsoresource: (gdbus) fix catching errors when we can't get the proxy

slyon/debian-libfsoframework,slyon/debian-libfsoframework,slyon/debian-fso-usaged,slyon/debian-fso-deviced,slyon/debian-fso-usaged,slyon/debian-fso-deviced